BL-C2 in 7.62x54R HIGH PRESSURE

[soonerfan66]

Out of H4895 but had some BL-C2 . Loaded some test rounds using Hornady data . First 2 shots showed signs of high pressure . I stopped and pulled bullet on a round and checked charge , it was good , COAL is also good . The data was for .308 bullet but have always heard even tho it takes a .311 bullet in Mosin it's ok . Data shows for 303 Brit and 7.7 Jap with .311 bullet charge is about 42gr but it shows 52gr for 7.62x54r with .308 . Is the large bullet diameter causing the pressure signs , do I need to drop charge some . The 52gr is minimum suggested and 55.5 max . with .308 .

 

[entropy]

I did some 7.62x54R's with BL-C(2) at the minimum charge, also using .308 bullets. Pressure signs indicated on the high side, I stopped there. I prefer IMR 4064 for 7.62x54R. IMR 3031 and Varget worked well also. My hunting load uses IMR 4064 and the 180 CT bullet. I don't know the charge off the top of my head, but it was more than accurate enough for a WI deer and bear round.

 

[Demi-human]

. The data was for .308 bullet but have always heard even tho it takes a .311 bullet in Mosin it's ok . Data shows for 303 Brit and 7.7 Jap with .311 bullet charge is about 42gr but it shows 52gr for 7.62x54r with .308 . Is the large bullet diameter causing the pressure signs , do I need to drop charge some . The 52gr is minimum suggested and 55.5 max . with .308 .

Regardless the reason for the high pressure, it can be solved with less powder.

If the bullet fits the bore tightly it can make better use of the pressure, but the chamber pressure comes from the amount of powder.

 

[soonerfan66]

Thinking problem may be in the bullets . I picked them up at a pawn shop , they were pulled bullets . I checked a few for diameter and seemed ok . But plan to go threw them all and double check size . Maybe a few odd ball bullet got in the mix ?????? Someone suggested maybe the pulled bullets got out of round . Been shooting .311 for years in this rifle , its been slugged . My preferred powder is H4895 but been out and was able to grab some of BL-C2 before prices went crazy . I have IMR4064 also and have used it in the past with good results but trying out the BL-C2 to dial it in . Was wondering why the charge for 303 and 7.7 are so much lower then for 7.62x54 . Same size bullet .

 

[Charlie98]

Was wondering why the charge for 303 and 7.7 are so much lower then for 7.62x54 . Same size bullet .

They are 3 different cartridges? The x54R is actually a pretty substantial cartridge viewed in it's own right.

 

[rule303]

The .303 SMLE action is nowhere near as strong as the Mosin Nagant. The Arisaka is in general, but most loading manuals are very conservative on the 7.7 due to the "last ditch" rifles of uncertain metallurgy. Factory 7.62x54 falls between .308 and .30-06 ballistics, quite a bit of a step up from .303 MkVII.

 

[Demi-human]

Thinking problem may be in the bullets . I picked them up at a pawn shop , they were pulled bullets . I checked a few for diameter and seemed ok . But plan to go threw them all and double check size . Maybe a few odd ball bullet got in the mix ?????? Someone suggested maybe the pulled bullets got out of round . Been shooting .311 for years in this rifle , its been slugged . My preferred powder is H4895 but been out and was able to grab some of BL-C2 before prices went crazy . I have IMR4064 also and have used it in the past with good results but trying out the BL-C2 to dial it in . Was wondering why the charge for 303 and 7.7 are so much lower then for 7.62x54 . Same size bullet .

Because, as stated, the rifles for these bullets are what they are.
If you are seeing high pressure, then, it is.
If you refuse to see it, well, the bullets are too big, or your scale is off, regardless your eyes will not understand.

Pressure is pressure, size not withstanding.

 

[Random 8]

52-55.5 seems WAY high for X54R. Hodgdon lists a similar range for 30-06/150 gr at the ceiling of pressure for that round that has a higher case capacity. I used to load .308 Win with this powder and 49.5/150 gr was absolute ceiling max, and only on a cold day.

IN WHAT EDITION HORNADY MANUAL DO YOU FIND THIS DATA? Just checked 5th through 10th and it ain't there. Nothing in Lyman or Hodgdon online either. Edit...I did find the data on Hodgedon online, matching your charge weights for 150 grain bullets. This still seems very hot compared to H4895 and Varget data which are of similar burn speed. I would contact Hodgedon directly. They can and do make errors.

 

[soonerfan66]

I bought these bullets from a pawn shop and they are pulled bullets . I miked them and tried to eyeball them best I could . A few seemed off a little rest looked ok best could tell . I loaded one test round back up , same charge and COAL . Bolt opened fine and brass came out fine and primer showed no signs off high pressure . So guessing was out of round bullets ???? Never heard of that issue before . I chunked the ones that looked off . Not sure if to try and use the the ones that look ok or should toss whole batch .

 

[Swampman]

Out of H4895 but had some BL-C2 . Loaded some test rounds using Hornady data . First 2 shots showed signs of high pressure . I stopped and pulled bullet on a round and checked charge , it was good , COAL is also good . The data was for .308 bullet but have always heard even tho it takes a .311 bullet in Mosin it's ok . Data shows for 303 Brit and 7.7 Jap with .311 bullet charge is about 42gr but it shows 52gr for 7.62x54r with .308 . Is the large bullet diameter causing the pressure signs , do I need to drop charge some . The 52gr is minimum suggested and 55.5 max . with .308 .

First off, if you're getting pressure signs you definitely need to back off on your charge.

Second, what weight are the bullets supposed to be and did you personally weigh a few to check?

What did the bore slug when you checked it?

What primer were you using?

I know it's unlikely at this time of year, but was the rifle or ammo hot?

To answer your question about why the 54r uses so much more powder than a .303, look at the case capacities.

A 7.62x54r case will hold 8 grains more water than a .303 and less than 4 grains under what an '06 will hold. In addition, maximum CIP pressure for the 54r is almost 4,000 psi higher than .303.

I wouldn't toss any of the bullets. You can get a Lee push through bullet sizing die for @ $20 that'll take care of any out-of-round bullets. It's a good thing to have around, especially if you buy a lot of pulled bullets.