I found a note on a couple vendor's website saying ammon reloaded with the RCBS 2 die set (pn: 15503) should not be used in bold action guns. Its a small base die set. I understand it sizes the brass a little bit smaller so it will feed better in semi-autos. Why is that bad for a bolt gun? Is it simply a matter of a lose fit in the chamber effecting accuracy or is there something else to it?
RCBS die set (pn: 15503) for bold action
- Thread starter BillSmith
- Start date
Don Fischer
New member
I've never used a small base die so I'm probably not the best to reply but. My guess would be that if it size's everything down a bit more that it could make a case being under sized. That could lead to a problem with case head splitting or maybe the body splitting. The reason so many partial size with FL dies is to make a case that fit's the chamber without over working the case.
The reason is much what Don Fisher speculated it would be. Bolt guns should have chambers that match SAAMI dimensions. Small base dies size the case to below SAAMI dimensions to ensure it functions properly in semi-automatic rifles whose chambers may vary in size. Routinely under-sizing cases can lead to their premature failure.
In my experience, however, all four of my semi-automatic rifles have chambers that match SAAMI dimensions almost exactly. I load ammunition for them using a regular (not small base) die set and have never had any problems.
On the other hand, it takes a rather authoritative use of the bolt on my Savage Axis to get a round to chamber and it comes out of the chamber after firing smaller than it was when it went it. This has caused me to segregate a batch of brass specifically for my Savage that has been fire-formed to its diminutive chamber and is now only neck sized.
I think it's a misunderstanding. Brass expands to fill the chamber starting at around the 12,000 psi mark, after which it becomes the size of the chamber for the rest of the pressure cycle. Moreover, I can't think of a small base die that actually gets you below the SAAMI diameter standard, which allows for a 0.008" span. RCBS says their small base dies simply have the shoulders a couple thousandths closer to the base. This is to help feed and extraction in self-loaders and lever guns. They don't say you can't use it in a bolt gun; just that a standard die is recommended for a bolt gun. The accuracy may be a little bit lower from the looser fit and case life will definitely be shorter from working the brass more at each load cycle.
To minimize overworking with a small base die, adjust it so it only sets the shoulder back a couple of thousandths. If you don't have a comparator to do that with, at the setup step where you screw the die into contact with the shell holder, slip a 0.002" feeler gauge between the deck of the shell holder and the die mouth during setup. This is not as good as the comparator, but its a starting point.
To minimize overworking with a small base die, adjust it so it only sets the shoulder back a couple of thousandths. If you don't have a comparator to do that with, at the setup step where you screw the die into contact with the shell holder, slip a 0.002" feeler gauge between the deck of the shell holder and the die mouth during setup. This is not as good as the comparator, but its a starting point.
RCBS’ website says their small base sizer die resizes cases below SAAMI minimums, reducing the shoulder and body by a few thousandths. Also says not recommended for bolt action rifles, but doesn’t say don’t use for bolt action rifles.
http://rcbs.com/Products/Dies-by-Ca...-Sizer-Die-Group-A-Popular-Rifle-Cartrid.aspx
http://rcbs.com/Products/Dies-by-Ca...-Die-Set-Group-A-Popular-Rifle-Cartridge.aspx
http://rcbs.com/Products/Dies-by-Ca...-Sizer-Die-Group-A-Popular-Rifle-Cartrid.aspx
http://rcbs.com/Products/Dies-by-Ca...-Die-Set-Group-A-Popular-Rifle-Cartridge.aspx
Bold action; Bolt action:
I have small base dies, I do not use them but I have them JIC. I also have BAR dies and I have dies that I consider 'mistakes', the mistake dies try to keep ever cases I shove into them. The inside diameter of my 'mistake' dies is sooo small I can not stick a case head into the big end of the dies.
F. Guffey
I have small base dies, I do not use them but I have them JIC. I also have BAR dies and I have dies that I consider 'mistakes', the mistake dies try to keep ever cases I shove into them. The inside diameter of my 'mistake' dies is sooo small I can not stick a case head into the big end of the dies.
F. Guffey
Higgite,
If you read my post more carefully, you will see I was only referring to diameters not going below SAAMI standard minimums, but did relate that the shoulder is 0.002" shorter, and that part is below SAAMI standard minimum. I take "not recommended" to mean it won't produce best results in a bolt gun and not because there is any intrinsic safety issue with it. If there were a serious safety issue with firing undersized cases in a bolt action rifle, none of the Ackley Improved cartridges could have their cases formed by firing their parent cartridges in the larger AI chambers. But that was Ackley's standard operating procedure and it still works fine today.
One day at a public range, a fellow came up to me with a fired case with no neck and asked if it was normal. The headstamp proved it to be a .308 Win case; or at least it had been. Definitely not normal. He had fired it in a rifle he borrowed to go hunting. I had to point out to him the barrel of the rifle was stamped ".30-06". (He was hopping mad that his friend had misinformed him about the chambering and got him to waste money on a box of the wrong ammunition. Some people aren't ready to go shooting.) Despite the .308 having a shoulder slightly wider than a .30-06 chamber if the chamber is at minimum SAAMI standard diameter and the case is at maximum SAAMI standard diameter, he could chamber the .308's in the '06 because the dimensions weren't at those extremes. No real accuracy, though. He couldn't get on paper with it, though that may not have been the fault of the misfit ammunition.
If you read my post more carefully, you will see I was only referring to diameters not going below SAAMI standard minimums, but did relate that the shoulder is 0.002" shorter, and that part is below SAAMI standard minimum. I take "not recommended" to mean it won't produce best results in a bolt gun and not because there is any intrinsic safety issue with it. If there were a serious safety issue with firing undersized cases in a bolt action rifle, none of the Ackley Improved cartridges could have their cases formed by firing their parent cartridges in the larger AI chambers. But that was Ackley's standard operating procedure and it still works fine today.
One day at a public range, a fellow came up to me with a fired case with no neck and asked if it was normal. The headstamp proved it to be a .308 Win case; or at least it had been. Definitely not normal. He had fired it in a rifle he borrowed to go hunting. I had to point out to him the barrel of the rifle was stamped ".30-06". (He was hopping mad that his friend had misinformed him about the chambering and got him to waste money on a box of the wrong ammunition. Some people aren't ready to go shooting.) Despite the .308 having a shoulder slightly wider than a .30-06 chamber if the chamber is at minimum SAAMI standard diameter and the case is at maximum SAAMI standard diameter, he could chamber the .308's in the '06 because the dimensions weren't at those extremes. No real accuracy, though. He couldn't get on paper with it, though that may not have been the fault of the misfit ammunition.
Nick,
I assume that when RCBS says reducing body and shoulder, they mean squeeze the body OD and bump the shoulder, but that's just an assumption on my part. (Yeah, I know about assume.
) As for the "not recommended" part, I was just pointing out what RCBS says as opposed to what the OP said vendors were saying. I agree with your take on that, "not recommended" doesn't mean unsafe or don't do it, or they would say so.
That .308/.30-06 story is a doozy. Public ranges can be scary at times.
I assume that when RCBS says reducing body and shoulder, they mean squeeze the body OD and bump the shoulder, but that's just an assumption on my part. (Yeah, I know about assume.
) As for the "not recommended" part, I was just pointing out what RCBS says as opposed to what the OP said vendors were saying. I agree with your take on that, "not recommended" doesn't mean unsafe or don't do it, or they would say so.That .308/.30-06 story is a doozy. Public ranges can be scary at times.
Jim Watson
New member
Hdwhit has a good point. I have heard of other Savage bolt actions, and some 99 lever actions with minimum or undersize chambers calling for small base dies.
Tolerances are in the multiple whole thousandths. This ain't watchmaking.
Tolerances are in the multiple whole thousandths. This ain't watchmaking.
F. Guffey
If you have to go with a small base die, wouldn't that be caused by the chamber being cut to small , if the chambers were cut to specs , whether semi , pump , lever or bold action . Sorry I just had to say it. There would be no need for a small base die , is that correct.
If you have to go with a small base die, wouldn't that be caused by the chamber being cut to small , if the chambers were cut to specs , whether semi , pump , lever or bold action . Sorry I just had to say it. There would be no need for a small base die , is that correct.
Many thanks to those of you who's replies addressed the question asked. Your input is greatly appreciated. You have helped me move a little closer to ballistic enlightenment.
For those like me with a short attention span and having trouble staying on topic the original question was "Why is that bad for a bolt gun? Is it simply a matter of a lose fit in the chamber effecting accuracy or is there something else to it?".
For those like me with a short attention span and having trouble staying on topic the original question was "Why is that bad for a bolt gun? Is it simply a matter of a lose fit in the chamber effecting accuracy or is there something else to it?".
The old feeler gage, I am 'THE FAN', I understand there are many reloaders that just can not deal with the thought of using the feeler gage. And then? There is the measuring before and again after; I believe it is safe to say I am the only reloader that has sized and compared cases that have been sized with full length sizing dies and cases that have been sized with a small base die.
One more time: I have RCBS BAR dies, I do not believe I would be bragging to say I have at least 4 sets. Back to the feeler gage, I have said at least 40 times one of my favorite uses for the feeler gage is to increase the presses' ability to overcome the cases ability resist sizing. HOW? It seems after discussing it 40 times a few reloaders would be caught up but on the outside chance many were not listening/reading I will try again.
I can place a feeler gage between the deck of the shell holder and case head when increasing the presses ability to overcome the cases ability to resist sizing. I can accomplish the same procedure with a small base die and I can accomplish the same task by grinding the top of the shell holder or base of the die.. No one is equipped better for grinding dies and shell holders; I have three grinders that make pilots, grinds angles and grinds to length. I do not grind shell holders and or dies because I do not find it necessary.
Again: I have dies that are mistakes, I have dies that keep ever case that is shoved into them, small base dies have a subtle difference when compared to minimum length/full length sizing dies. There is nothing subtle about my 'mistake' dies, if a reloader calls and complains the manufacturer they will ask the reloader how the inside diameter was measured. The standard response from the manufacturer makes the claim the round hole in the die can not be measured with a dial caliper. AGAIN: I TURN THE CASE AROUND AND STUFF THE CASE HEAD INTO THE big end of the die. My mistake dies will not allow the case head to fit into the large end of the die; it is not a matter of 'how far?', the case head is too large in diameter to fit into the die.
And then there has to be something about the taper reloaders do not understand, I am worried about running out of ink in my key board, we went wireless, we got help from our 11 year old granddaughter, it was about that time the granddaughter reported me to her grandmother. It seems I broke my keyboard because she could not find the keys because the letters no longer existed.
F. Guffey
Mr. Guffey,
My C, D, and S keys went blank some time ago (Microsoft wireless keyboard) and the N is down to the bottom edges of the letter.
Here, because I was undoing the extra shortness of the SB die, I suggested the feeler gauge used the opposite way from your method of increasing sizing, instead setting it on top of the deck for setting up the SB die to behave like a longer standard die. Feeler gauges are very versatile in that they can do both shrinking and growing of sizing this way.
I did get one of Redding's Competition Shell Holder sets to make cases come out even longer, but found feeler gauge washers that accomplish the same thing. I also use feeler gauge washers under the head of a Sinclair priming tool to fix the ram height to get a specific primer seating depth. Works a treat.
Bill,
Basically, yes, best accuracy and shorter case life (fewer reloads per case before incipient head separation or splits). For a long time, the benchrest crowd relied on neck sizing only for better accuracy, and many still use. These days you see more BR people talking about bumping the shoulder back a thousandths or two from the tightest fit to let the taper of the shoulder self-center in the case. I think part of the reason this changed over time is the methods of measuring headspace changed. In the 1950's the .30-06 was still winning the Wimbledon Cup, but that cartridge is from a time when headspace was measured from the case head to the chamber's side wall and shoulder intercept. To get the case to headspace on that corner, they made the chamber with a very slightly shallower shoulder angle than the case (all the .30-03 descendants are like that, with .30-06 and .270 Winchester being most popular). So the case had that weaker contact with the shoulder and I think neck sizing only benefits those cases more than modern designs where the case and chamber shoulders have matching angles, which benefit more from a little setback. But this is speculation on my part, and not proved. The bottom line is that top accuracy loaders have cases that fit their chambers fairly closely and the small base die works against that.
Recently, board member Hummer70, who has been the National Palma Match (1000 yard) champion twice, sent me a chamber reamer design that is just for Federal Gold Medal .308 Winchester loaded with the 168 grain Sierra MatchKing. It is all about getting that ammunition to tighter, better aligned fit.
Higgite,
It dawns on me (sometimes dawning is a slow process for me) that since small base dies are meant to overcome the spring-back of cases fired in generous chambers, which requires squeezing them an extra two or three thousandths, that some might be made so that diametric undersizing is possible if you start with a case fired in a very tight chamber. The two SB dies I have don't go quite that small, but they aren't RCBS. So I emailed RCBS to see if theirs might be that small. I'll post what I learn.
My C, D, and S keys went blank some time ago (Microsoft wireless keyboard) and the N is down to the bottom edges of the letter.
Here, because I was undoing the extra shortness of the SB die, I suggested the feeler gauge used the opposite way from your method of increasing sizing, instead setting it on top of the deck for setting up the SB die to behave like a longer standard die. Feeler gauges are very versatile in that they can do both shrinking and growing of sizing this way.
I did get one of Redding's Competition Shell Holder sets to make cases come out even longer, but found feeler gauge washers that accomplish the same thing. I also use feeler gauge washers under the head of a Sinclair priming tool to fix the ram height to get a specific primer seating depth. Works a treat.
Bill,
Basically, yes, best accuracy and shorter case life (fewer reloads per case before incipient head separation or splits). For a long time, the benchrest crowd relied on neck sizing only for better accuracy, and many still use. These days you see more BR people talking about bumping the shoulder back a thousandths or two from the tightest fit to let the taper of the shoulder self-center in the case. I think part of the reason this changed over time is the methods of measuring headspace changed. In the 1950's the .30-06 was still winning the Wimbledon Cup, but that cartridge is from a time when headspace was measured from the case head to the chamber's side wall and shoulder intercept. To get the case to headspace on that corner, they made the chamber with a very slightly shallower shoulder angle than the case (all the .30-03 descendants are like that, with .30-06 and .270 Winchester being most popular). So the case had that weaker contact with the shoulder and I think neck sizing only benefits those cases more than modern designs where the case and chamber shoulders have matching angles, which benefit more from a little setback. But this is speculation on my part, and not proved. The bottom line is that top accuracy loaders have cases that fit their chambers fairly closely and the small base die works against that.
Recently, board member Hummer70, who has been the National Palma Match (1000 yard) champion twice, sent me a chamber reamer design that is just for Federal Gold Medal .308 Winchester loaded with the 168 grain Sierra MatchKing. It is all about getting that ammunition to tighter, better aligned fit.
Higgite,
It dawns on me (sometimes dawning is a slow process for me) that since small base dies are meant to overcome the spring-back of cases fired in generous chambers, which requires squeezing them an extra two or three thousandths, that some might be made so that diametric undersizing is possible if you start with a case fired in a very tight chamber. The two SB dies I have don't go quite that small, but they aren't RCBS. So I emailed RCBS to see if theirs might be that small. I'll post what I learn.
There are reloaders that answer ever question with "You gotta get you one of those small base dies"! I believe a reloader should have the ability to measure the diameter of the chamber and length of the chamber from the shoulder/datum to the bolt face. I believe reloaders should find someone that can give them a short course on threads. All of my presses and dies have threads, when it comes to increasing the length of the case from the shoulder to the case head most reloaders are out of luck because the manufacturer does not sell cases to reloaders like me; I have no problem dealing with a case that will not allow the bolt to close because long cases from the shoulder to the case heads are my favorite cases.
I have forming dies, the forming die forms cases that are too large in diameter and too long from the shoulder to the case head, When I form cases there is no such thing as a chamber that is too long from the shoulder to the bolt face or too large in diameter; example, I shorten a 30/06 case from the shoulder to the case head .127" when forming 8mm57 cases. BUT! It would be mindless of me to form the 8mm57 cases to specifications. I determine the length of the chamber from the shoulder to the bolt face first because I form first and then fire. Most reloaders form the case and then fire form the case, I do not believe all of that work is necessary.
F. Guffey
Unclenick and F. Guffey,
Thanks for these most recent replies. Several very interesting points in them. My favorites are:
"accuracy and shorter case life" - Okay, so I got the basics of it right..
"top accuracy loaders have cases that fit their chambers fairly closely and the small base die works against that" - That makes sense, thank you.
"So I emailed RCBS" - I would very much like to hear what they say and am looking forward to your post.
"National Palma Match (1000 yard) champion twice" - Clearly someone who is doing something right. When you say "chamber reamer" you're talking about actually re-cutting the chamber, right? Grinding off metal to change it's shape/size? In this case cutting it specific to one particular factory load spec, right? Now that really is interesting. I always thought the way the game was played was to make your brass fit the gun and then experiment with different primer/powder/bullet profile/bullet weight combinations to find what that gun likes the best. All centered around tuning your reload to a particular gun. Re-cutting the chamber to a factory load spec is the exact opposite. Tuning the gun to the ammo. Unless I misunderstood and got that all wrong, what are the pros and cons?
It's also interesting that Federal GM 168gr Sierra MatchKing comes up again. Thats what Savage, and many other people I have spoken to, have recommended as a starting point
Many thanks for the insights,
Bill
Thanks for these most recent replies. Several very interesting points in them. My favorites are:
"accuracy and shorter case life" - Okay, so I got the basics of it right..
"top accuracy loaders have cases that fit their chambers fairly closely and the small base die works against that" - That makes sense, thank you.
"So I emailed RCBS" - I would very much like to hear what they say and am looking forward to your post.
"National Palma Match (1000 yard) champion twice" - Clearly someone who is doing something right. When you say "chamber reamer" you're talking about actually re-cutting the chamber, right? Grinding off metal to change it's shape/size? In this case cutting it specific to one particular factory load spec, right? Now that really is interesting. I always thought the way the game was played was to make your brass fit the gun and then experiment with different primer/powder/bullet profile/bullet weight combinations to find what that gun likes the best. All centered around tuning your reload to a particular gun. Re-cutting the chamber to a factory load spec is the exact opposite. Tuning the gun to the ammo. Unless I misunderstood and got that all wrong, what are the pros and cons?
It's also interesting that Federal GM 168gr Sierra MatchKing comes up again. Thats what Savage, and many other people I have spoken to, have recommended as a starting point
Many thanks for the insights,
Bill
What dies RCBS say: RCBS says the Rock Chucker is a cam over press. I say I can measure cam over, I say I have 11 cam over presses, I say I have 3 Rock Chucker presses: not one of my Rock Chucker presses cam over. So? It is safe to say I am the only reloader that has the equipment and ability to measure cam over.
Back to what RCBS/Sierra says: In the back of their reloading manual in the Glossary of Terms RCBS says a small base die is a good fitting full length sizing die. I have suggested reloaders remove the primer punch/sizer plug assemble to gain accesses to the bottom of the die, After removing the assemble I have suggested the reloader stick the big end of the case into the opening of the die. I will say it is a safe bet not one reloader has checked the fit between the base of the die and case head.
Again, I have dies, I have lots of dies, there are subtle differences' between my dies; again, I have dies that have an opening that is too small to allow a case head to fit into the die opening.
SMALLER THAN: LARGER THAN: I have sizing dies that are .005" smaller in diameter than a standard die. The dies with the small diameter are not small base dies, they are really small base dies, I know, most reloadrs believe they have small chambers and a really small base die is what they need but they do not consider the case head thickness of the case. I have thick headed cases that measure .260 from the cup above the web to the case head that will lock up my press because of the shell holder. Unlike most my shell holders have a deck height of .125" meaning the shell holder prevents the bottom .125" of the case to be sized and then there is the reason I can place the case head into the die opening. The reason: The die has radius, the radius helps me when sizing, the radius starts the forming process, without the radius the die keeps the case. Meaning? I have one sizing die that keep the first 5 cases I tried to size. What do I know about the die? I know I can not insert a case head into the die opening. What do I know about the case head that will not fit the die opening? I know the case has not been hammered with a heavy load and the case head will fit all of my other 30/06 sizing dies.
Compare? I have small base dies, I have BAR dies, the opening is not as small as reloaders are lead to believe, back to the feeler gage, I can reduce the length of the case from the shoulder to the case head by placing a feeler gage between the deck of the shell holder and case head when sizing. As I have said; "there has to be something about the taper reloaders do not understand". Because placing the shim/feeler gage between the deck of the shell holder and case head reduces the diameter of the case head.
And then there is all of the confusion, it is impossible to size the case head because of the deck height of the shell holder. Again, my shell holders have a deck height of .125". Reloaders should have know this from the old days, I have two C&H die sets with the instructions on the bottom of the box. The box is a counter top display box with the flip up lid. The instructions on the bottom of the box read: Use these dies with shell holders that have a height of .125". I added the 'deck' part. The C&H dies were made in El Monte California in the late 60s.
F. Guffey
Back to what RCBS/Sierra says: In the back of their reloading manual in the Glossary of Terms RCBS says a small base die is a good fitting full length sizing die. I have suggested reloaders remove the primer punch/sizer plug assemble to gain accesses to the bottom of the die, After removing the assemble I have suggested the reloader stick the big end of the case into the opening of the die. I will say it is a safe bet not one reloader has checked the fit between the base of the die and case head.
Again, I have dies, I have lots of dies, there are subtle differences' between my dies; again, I have dies that have an opening that is too small to allow a case head to fit into the die opening.
SMALLER THAN: LARGER THAN: I have sizing dies that are .005" smaller in diameter than a standard die. The dies with the small diameter are not small base dies, they are really small base dies, I know, most reloadrs believe they have small chambers and a really small base die is what they need but they do not consider the case head thickness of the case. I have thick headed cases that measure .260 from the cup above the web to the case head that will lock up my press because of the shell holder. Unlike most my shell holders have a deck height of .125" meaning the shell holder prevents the bottom .125" of the case to be sized and then there is the reason I can place the case head into the die opening. The reason: The die has radius, the radius helps me when sizing, the radius starts the forming process, without the radius the die keeps the case. Meaning? I have one sizing die that keep the first 5 cases I tried to size. What do I know about the die? I know I can not insert a case head into the die opening. What do I know about the case head that will not fit the die opening? I know the case has not been hammered with a heavy load and the case head will fit all of my other 30/06 sizing dies.
Compare? I have small base dies, I have BAR dies, the opening is not as small as reloaders are lead to believe, back to the feeler gage, I can reduce the length of the case from the shoulder to the case head by placing a feeler gage between the deck of the shell holder and case head when sizing. As I have said; "there has to be something about the taper reloaders do not understand". Because placing the shim/feeler gage between the deck of the shell holder and case head reduces the diameter of the case head.
And then there is all of the confusion, it is impossible to size the case head because of the deck height of the shell holder. Again, my shell holders have a deck height of .125". Reloaders should have know this from the old days, I have two C&H die sets with the instructions on the bottom of the box. The box is a counter top display box with the flip up lid. The instructions on the bottom of the box read: Use these dies with shell holders that have a height of .125". I added the 'deck' part. The C&H dies were made in El Monte California in the late 60s.
F. Guffey
RCBS response
RCBS got back to me. What their man said is they take the SAAMI minimum dimensions and reduce them by -0.003" and machine to ±0.002". In other words, if you buy one of these dies, they could be anywhere from -0.001" to -0.005" smaller in diameter than a minimum sized case. In the case of -0.001", springback will certainly put the cases back within SAAMI minimum dimensions. In the case of -0.005", even a grossly oversized case from a loose full-auto chamber will not spring all the way back to SAAMI minimum size. So it turns out the true answer depends what individual die you happened to get as to whether your resized cases come out inside the SAAMI lines or not.
Bottom line: measure results and adjust the die settings accordingly.
RCBS got back to me. What their man said is they take the SAAMI minimum dimensions and reduce them by -0.003" and machine to ±0.002". In other words, if you buy one of these dies, they could be anywhere from -0.001" to -0.005" smaller in diameter than a minimum sized case. In the case of -0.001", springback will certainly put the cases back within SAAMI minimum dimensions. In the case of -0.005", even a grossly oversized case from a loose full-auto chamber will not spring all the way back to SAAMI minimum size. So it turns out the true answer depends what individual die you happened to get as to whether your resized cases come out inside the SAAMI lines or not.
Bottom line: measure results and adjust the die settings accordingly.
`long before the Internet there was the 30/06, it has always been assumed there was only one chamber for the 30/06 but somewhere around or to either side of 1936 the M1 Garand was invented. The Garand was/is a auto feed semi auto feed rifle so someone had to decide what ammo was going to be used. All 30/06 rifles up to that point used one round and we knew two different rounds was not going to work so someone decide to change the chamber in the M1, they cut the chamber with clearance, they did not add a lot of clearance but they increased the diameter of the chamber.000246" at the base.
And then? There is always a 'and then' moment I was told they could not hold tolerances that close and I wondered about the Pratt & Whitney gage, it was set up to measure .000005", I found it almost useless because the thickest measurement it would make was not much thicker. SO I removed the electronics and added a dial indicator that gets down to .0001" and opens up to 5 inches, anyhow, it is one smooth running height gage.
As to the other 30/06 chamber: Back in the ole days they had a Match Chamber.
We as in the US has been involved in some clandestine events, we had to be careful what ammo we furnished to the conflict. I have some 30/06 ammo and cases that we did not make but I thought was interesting. Not knowing why the ammo was made or who/ what arsenal made the ammo, in the beginning I thought the cases were designed to off set the lengt6h of the chamber.
F. Guffey
And then? There is always a 'and then' moment I was told they could not hold tolerances that close and I wondered about the Pratt & Whitney gage, it was set up to measure .000005", I found it almost useless because the thickest measurement it would make was not much thicker. SO I removed the electronics and added a dial indicator that gets down to .0001" and opens up to 5 inches, anyhow, it is one smooth running height gage.
As to the other 30/06 chamber: Back in the ole days they had a Match Chamber.
We as in the US has been involved in some clandestine events, we had to be careful what ammo we furnished to the conflict. I have some 30/06 ammo and cases that we did not make but I thought was interesting. Not knowing why the ammo was made or who/ what arsenal made the ammo, in the beginning I thought the cases were designed to off set the lengt6h of the chamber.
F. Guffey