Is this Deep seating Frontier bullet SAFE ?

S

Saguaro 66

New member
Good Morning gentleman,

As I mention in another post, thanks to your help, I'm into reloading the sweet classic British 300H&H.

I got many inexpensive Frontier flat nose 220g bullets from South Africa. I plan to use for practice.

I'm starting with a conservative 56 grains of N160
However when the bullet is seated I have to go very deep into the case so the bullet doesn't touch the rifling and I can lock the bolt without difficulty. So only about 25% of the bullet is visible.

Due to the relatively low charge of powder --about 82%-- the case is not yet full and powder moves freely inside.

55,5 g of N160 is about the minimum charge recommended for a 220 g R.N is this cartridge.

My question is.... can this deep seating create an over pressure or any other major inconvenience?

Thanks a lot !
 
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55,5 g of N160 is about the minimum charge recommended for a 220 g R.N is this cartridge.
Click to expand...

My question is.... can this deep seating create an over pressure or any other major inconvenience?
Click to expand...

It is not as thought your are being forgiven but the 'near minimum load' and the deep seated bullet off set the effect of high pressure. I would suggest you determine the distance from the bolt face to the lands, I do not seat bullets to the lands but I do want to know where they are.

I have tested rifles that 'jus did not shoot' and had no obvious reason for the problem. When determining the distance from the bolt face to the lands I have found I could push bullets out of the case and could hear the bullet skidding between the neck of the case to the lands. It was not funny but one friend built magnificent rifles, I demonstrated his bullets were skidding between the neck of the case to the rifling over .225" before contact; he asked me what caused that and I had to say in all honesty, "I DO NOT KNOW". He made the reamer.

F. Guffey
 
I agree with The Guff for a change.
The first English Vihtavuori pamphlet discussed bullet setback vs chamber pressure. A straight handgun case didn't do anything but increase pressure as the bullet was seated deeper.
A bottleneck rifle round first showed a decrease in chamber pressure as the bullet came back away from the lands, and it had to be seated pretty deep to reduce chamber volume enough to increase the pressure.
I think you are ok working near the starting load. That's what those are for.
 
Thanks Guffey,

I already did what you suggest, and keep a distance with the lands. I took a picture to show the results of both seated different bullets.

The Sierra RN seated at a "normal" distance vs the Frontier FN way deep into the case.
Both off the lands . Both 220 g both 56 grains of N160

However the Frontier bullet due to its shape touches the lands very early and must go a lot into the case in order to be off the lands and to close easily the bolt.

They may not be the ideal bullet but I really I'd like to use the Frontier bullets for training because I got many of them and are unsuitable for our local hunting.

Does this deep seating of the Frontier bullet create any danger or disadvantage?
 

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Does this deep seating of the Frontier bullet create any danger or disadvantage?
Click to expand...

I would not use maximum loads with the bullet set back into the case, I would not look for a crushed load where the bullet is used to compress the powder, It is not a strange thing but moving the bullet out to the lands has the same effect when seating the bullet to and or into the lands.

Again, I am the fan of the running start, I want my bullets to have that jump and I understand when I seat the bullet into the case pressure increases. Again, I want to know the distance from the beginning of the rifling to the bolt face. To me there is nothing entertaining about seating a bullet at or into the rifling wondering if the bullet is going to get started before the pressure gets serious, I want the bullet past the beginning of the rifling before the bullet knows they are there.

And then there is 'the spike'.

F. Guffey
 
.........GUFFEY
It is not a strange thing but moving the bullet out to the lands has the same effect when seating the bullet to and or into the lands.........

..........

I had imagine it was not too safe this deep seating and you made the reasons clear to us all.

I shall stay in the mild charges with this bullets. They aren't easy to reload. No wonder they were so inexpensive.

I have no other option with this particular Frontier bullet and now I wonder how other reloaders deal with it because I have the same situation with 4 more .30 cal rifles. This bullet is long and has such a flat nose that unless is seated deed into the case the bolt can't be locked and the nose gets stock into the lands.

Thanks for sharing your thoughts and knowledge or this rather delicate passion we have.
 
56 grains of N160 is the start load for a 200 grain bullet. No 220 data on Vihtavuori's site, so you need to contact them and ask if they have any proper data or buy a manual with 220 grain Vihtavuori data in it. Do not make up your own data.
Hodgdon's site does have 220 grain data and gives 3.580" at the OAL. Use that OAL and you'll be fine. But find proper data.
This, from 2002, has N160 220 grain data. Max load is 65.1. Reduce by 10% for the start load gives 58.6. http://pdf.textfiles.com/manuals/FIREARMS/vihtavouri.pdf
 
Running parallel calcs in Quickload:

300 H&H
Lyman 311290 220gr LRN-GC
V-N160/56.0gr
OAL: 3.134" (and yeah, there's only about a quarter of the bullet beyond the case mouth)
Pressure: 38,400*psi/2,300fps (24")


*
(postscript: That's a 62,000psi cartridge)
 
Thanks Mehavey, good to hear that. I'm glad I can use this Frontier for practice and it looks like I can still add a few more grains and still be within safe margins

Apparently this Quickload software is a good investment for intrepid handloaders


Just for the record I did measure the velocity of this Frontier bullet and it was the same velocity as the Sierra RN of the same 220g but seated 'normally' as recommended by Sierra .
However ..... and I have no idea if this is irrelevant or purely subjective , the felt recoil was harder with the Frontier, maybe because it's a harder bullet or it's got more drag ?

.

Nevertheless it'd be good to know how deep seating affects internal ballistics.
 
I did measure the velocity of this Frontier bullet ...
Click to expand...
What was it (and what barrel length was used)?
Enquiring Minds Want to Know
;)



BTW: I went looking for Frontier Bullets but could not find the one you describe.
Can you provide a cite and/or a pic?

.
 
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There is a pic of both bullets above #4 I reckon
It's a South African bullet for very heavy animals , very inexpensive here
If you need a better pic of it I'll take care of it to-morrow.
 
That's good enough.

Calibrating QL's effective Burn Rate for that velocity/barrel length, I'm going to say 47ksi
 
Here is a pic of the South African Frontier bullets box.
On top of the box there are there is also a Sierra RN of the same 220 for comparison

I bought the Frontier bulles because they were very inexpensive --even for European standards-- with the idea of using them for practice.


MEHAVEY: "Calibrating QL's effective Burn Rate for that velocity/barrel length, I'm going to say 47ksi"

Sorry mate, I don't understand what you mean with that...
 

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