Boat tail bullet seating question

M

michaelcj

New member
I'm going to start reloading for my M1A.

My general understanding and practice in reloading for my other rifles is that:

"never seat a bullet so the base intrudes below the neck / shoulder intersection" ????

I have Hornady and Sierra bullets on hand and note that the boat tail types would intrude into the case if the OAL was 2.800 or less.

Not a problem with my 30.06 with its longer neck but with the .308 shorter neck this has me concerned.

The BT's I have here are 150 grain and I suspect the 165/8 would be even more "intrusive"

I can see that the 147gr FMJ's available are shorter bullets and that those with a cannalure seem to be designed for the .308/7.62x51 case.

Am I over thinking this??

What 150/55 and 165/68 bullets are recommended by those loading for .308 semi autos?

Thanks
Mike
 
If you followed the rule of never seating so the bullet base is below the case neck, many calibers would be nearly useless. Nearly all my .300 WM, .338 WM, and 7mm Rem. magnum loads have the bullets seated in that manner.
 
Thanks 454, Exactly why I asked the question.

My experience with reloading bottleneck cartridges is limited to:
.22 Hornet
30WCF
30.06
7x57

The issue has never come up with those rounds. I don't know where I may have come up with the idea that "intrusion" was a no no…. but asking is how one learns.
 
I have heard that advice for gas checked lead bullets, for the possibility of a check coming off and creating an obstruction - but no reason I can think of how it would be a problem with jacketed ones
 
Try that with a 77gr smk in a 223 loaded for an AR - haha . That bullet goes WAY past the neck base . I've loaded some 190gr smk in a 308 that were seated well below the base of the neck .

Start with minimum charge and seat where you want . Well you can seat to shallow . The rule there is at least the diameter of the bullet deep .
 
"never seat a bullet so the base intrudes below the neck / shoulder intersection" ????
Click to expand...

Its BS. There are factory rounds seated that way. (the reason it is BS is the word "never")

There is no need to do it, if you don't have to, it takes up some of the powder space. But with some bullets, you absolutely have to, its just a fact of life.

The loads are adjusted to compensate for this.

HEAVY bullets and boattails are the most usual ones you need to do this with.

Remember that you are limited to a maximum overall length, so the heavier bullet HAS to protrude more deeply into the case than the lighter one.

The BT's I have here are 150 grain and I suspect the 165/8 would be even more "intrusive"
Click to expand...

If you really want to see "intrusive" load a .308 Win with a 220gr RN.

Under educated (aka ignorant) people often claim the .308 "won't handle heavy bullets", meaning 200 & 220gr. That too is BS. The .308 will handle them just fine. What it won't do is shoot them as fast as some people think is needed.

Some RIFLES will not handle the 220gr bullets (semis, generally) that's not a flaw in the cartridge.

I've had FAL, HK 91, ARs (three different makers) and Springfield M1A.

All I ever used in any of them is the standard GI 150/147 FMJ bullets. I don't do match shooting, and I don't drag around a 9+lb semi auto for hunting when I can have the same round in a 7lb (or less) rifle. So I never bothered with hunting bullets in the semis, either.

My only recommendation is that you test a batch of everything, and if you find a combination that your rifle likes significantly better than the rest, buy a lot of them! ;)

Take a look at the loading manuals and you'll see they use the same data for flatbase and boat tail bullets of the same weight. DON"T worry about the BT sticking into the case a bit deeper, its a non issue if you are using data for THAT bullet.
 
HSM sells a load with the 80 grain SMK seated to magazine length. There's an actual small gap around the bullet ogive at the case mouth.
 
"...Am I over thinking this??..." Absolutely. Just seat 'em(150's or 168's) to 2.800" OAL and you'll be fine. The only difference between loading for a semi or a bolt action is that the semi requires FL resizing every time.
And FORGET THE CANNELURE.
 
The one thing you do want to watch out for is the dreaded donut. If you develop that inward ring you see on the upper sectioned case in the photo below, it can increase pressure to have the bullet seated through it. Mostly, though, it takes a while to develop, and I don't think any of my M1A cases ever had that problem before I retired the brass.

Most M1A shooters say not to reload a case more than 4 times for the M1A, as the risk of head separation gets too great. That's with military brass which is generally favored in that gun for its strength. I've run softer Remington cases 6 times with moderate loads and no problems. Just keep monitoring for an internal pressure ring down near the head and for that donut at the base of the neck, and you'll be fine.

If you own a .308 bolt gun or two, as I do, you can always retire brass from the M1A before the ring or donut forms and move it over to the bolt gun where minimum resizing will keep it going for a lot longer. You can also get an RCBS X die for sizing if you like. It has a mandrel that should be a hard stop against a donut of any kind ever forming in the first place.

If you get a donut, it can actually be cut out with an inside neck reamer. You can see the marks from that having been done before to the upper case in the photo. It was evidently kept alive for awhile; probably by a bolt gun shooter who resized it minimally or used it at low pressure, to judge from the lack of significant pressure ring inside.

IMG_0507B_zpsvmd4wxvy.jpg
 
The load chart will give you your safe range depending on what powder your 308 may be seated 2.750 with a 150 - 168gr. bullet. Magazine fed you can't go to long, I would think 2.810 a safe max. Used that weapon in the service, very nice piece of machinery. Good luck with it, very accurate.
 
I haven't purchased a die set for the 308 yet and have read a fair number of posts discussing Standard/Small Base/ X dies and their advantages-disadvantages for semi-autos.

The only other 308 I have is a pre64 Winchester 88 Lever gun in 308 and I don't anticipate a 308 bolt gun in my future.

The difference in cost between the different die sets isn't a concern for me.

So….. is there some sort of consensus that a small base set would be of any advantage or not?
 
michaelcj, I don't really know anything about small base dies. If the chamber isn't custom l would think a standard die set to .002 headspace you should be fine. If you weren't a reloader wouldn't store bought rounds work in your rifle, I would think they would. I shoot a bolt action, some of my friends neck size, I use to but found full sizing is working better for me & still getting just as many reloads as neck sizing only. Also watch case length. Your rifle is for shooting paper or steel the Sierra 168 gr. HPBT match king bullet over IMR 4064 41.5 gr. is an accurate load at 2.800 OAL with your setup. Hope I helped in some way.
 
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CW308…. I do reload and have for some years, just not 308 and for a gas gun. I've been loading .22 hornet, 7x57, 30.06, 30WCF and 45-70 and have a fairly extensive single stage set up and component supply…..

I have shot mostly NATO surplus through the M1A [mostly Australian] but that supply is dwindling and figured I might as well reload for it, especially for bullet weights types other than the 147FMJ.

I have everything on hand but Brass [the Aussie stuff is Berdan] and dies….

Thanks for the info
 
I know a good number of very experienced M1A/M14 shooters and none has every found they needed small base dies, nor do they know of anybody who did. Occasionally someone with an AR says they can't get reliable feed without one, but not M1A owners AFAIK.

Some have found that if they buy once-fired brass that went through a machine gun originally, that it is stretched to the point they have a very hard time getting it as small as their other brass. They will then sometimes resort to a small base die for the first resizing, but go to a standard die afterward for the rest. Others have standard dies they've had ground shorter at the mouth to solve that. Board member F. Guffey removes the decapping pin from the die and just slips a feeler gauge between the bottom of the obstinate case and the shell holder to get it sized smaller by the thickness of the gauge.
 
Michaelcj, from your post I know you reload. Being your shooting 7.62, I would reload 308 no different then any other reload. Gas operated would be a problem using light loads, my not cycle. Other then that treat it like any other reload. IMR 4064 41.5 gr. Under a 168 gr. Sierra HPBT Match King is a accurate load 2.800 OAL. A lot of my friends are using Varger & RL 15 Check out MidwayUSA for new casas.
 
Thanks Nick for a detailed answer I was looking for re: SB dies….. I have "tried" to read and understand Guffey's posts and I get his technique with the feeler gauge.

308 thanks for the suggestions.
 
There are two different ways to use the feeler gages and sizing cases that I know of .

1) is to use a feeler gage as a spacer to judge how long you size a case . Lets see if I can explain this . Lets say you want to size your cases from head to datum 1.630 . How ever when you FL size a case in your standard die . This means your die and shell holder make hard contact with press cam over . The case measurement from head to datum is 1.624 . How do you adjust your die ? You adjust the die so a .006 feeler gage can fit in between the shell holder and the die when ram is fully up . Meaning the ram is up and you screw down the die until it hits the feeler gage that is sitting on top of the shell holder

UtWOy7.jpg


The other way is if you want to size a case smaller from head to datum then your standard die will do . For this you place a custom cut feeler gage in between the case and the shell holder lifting up the case . This results in sizing the case smaller from head to datum .

k441.jpg
 
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