Comments on: .308 Winchester — Large vs. Small Flash Hole Test

By: Guy

Guy — Wed, 16 Sep 2015 18:39:29 +0000

If your going to test it why make the hole larger?? Seems to defeat the purpose of the test. The Palma brass works great and last forever.

By: Mikecr

Mikecr — Sat, 16 Nov 2013 21:21:39 +0000

Could the ES change with flasholes due to powder kernel fit. That is, larger flasholes would allow powder to settle/wedge in, where smaller flasholes might not.
Maybe the test should be run with powders of significantly different kernel size, barrel pointed upward, and with a focus on consistency of flash instead of amplitude(given powder difference and search for ES discrepancy).

By: Louie Louie

Louie Louie — Tue, 29 Mar 2011 15:12:06 +0000

While it may not offer much difference, the price is still less than the projected Lapua 260 Rem prices. Just gotta put up with the shorter neck.

By: Rob L

Rob L — Tue, 29 Mar 2011 02:52:45 +0000

I first became acquainted with the Rem BR case in the middle ’80’s due to my interest in the 22 CHeetah. For me IMR 4064 was NOT the powder of choice. IMR 4831 did better, but it wasn’t until I happened upon RL-15 that the cartridge began to approach its potential. I continue to shoot the cartridge today, and velocities of 4350 fps with 52 gr bullets are routine as are velocities above 4900 fps for a good 40 gr projectile. I decided years ago such velocities are made possible through the use of the SR primer because the ignition is large enough to light the powder charge but small enough to allow for more progressive burning than with a LR which flattens the pressure curve a bit. Don’t have any way of truly knowing whether I’m right or even close. What I can tell you is it took 4 years of trying every primer/powder combination before one that worked in every good way appeared. That being RL-15 with the Remington 71/2 primer of 80’s vintage. I still have some, the new one doesn’t yield the same consistency; CCI 450 seems to be better than either however.

I’ve tried the new Lapua case. Capacity isn’t the issue but the fact that the Lapua’s head measures 0.004″ larger than the old Rem BR’s is. My Cheetah chamber is a couple of thousandths too small for a workable fit.

By: Tim Bradford

Tim Bradford — Tue, 29 Mar 2011 00:12:52 +0000

I looks to me like in the rem. 7 1/2 primer, the small flash hole did create a smaller flash, but more of a “jet” effect (look closely). It also appears that primers with lesser flash or flame front tend to be more accurate. I’m thinking that the less effect the primer has on the overall load, the better off you are, since the hand loader has no control over the amount of priming compound from primer to primer. Also, I would suggest that the milder the primer, the less significant the size of the flash hole becomes.

By: Roy

Roy — Tue, 29 Mar 2011 00:09:16 +0000

The very early lots of the Rem brass was stamped only BR REM and with the .080 flash hole. This brass was indeed meant to be reformed into the 7BR,6BR and 22BR family of cartridges as REM was not producing them commercially. However, the very earliest production of the BR REM brass was produced with NO FLASH HOLE in the brass.This brass was released to Bench rest shooters who were experimenting with the BR Family of cartridges and the flash holes were drilled by the shooters to evaluate which size flash hole was optimum.Suffice to say that by the time the BR REM brass was released to the public, it arrived with the .080 flash hole in the case. You might make any conclusions as you wish.
I bought several cases of this brass when it became available and did a lot of testing with it, across a chrono and in match situations.What I found was that the small primer, REM 7/12, that I was using reached a point of diminishing marginal return in the BR REM case, ..er that is to say that after a certain point, adding more powder did not result in a increase in velocity or pressure, it simply left the barrel full of unburnt powder kernels.The powder that I tested was IMR 4064 and other powders might react differently.I do recall that the point of DMR was about 45 grains of IMR 4064 or so.
Many shooters used these cases and had very good success with them, mostly using IMR 4895 and less than 45 grains in their Palma loads. J.H.Franklin shot them with fantastic results and success.
The most unique aspect of these BR REM cases was their extremely light weight and vast powder capacity.If my memory is correct, the BR REM case was lighter than the WCC 58 cases of lore.I see the major difference between the BR REM and the Lapua Palma cases in not only the flash hole size, but the case capacity also.An inquisitive shooter might simply drill a .080 flash hole in 20 Lapua Palma 308 WIN cases and compare them with the standard flash hole cases.Interesting test.
In closing, with the new powders available today and the reduced capacity of the Lapua case from the BR REM case, there might very well be a MAGIC potion mix for the Palma shooter utilizing the Lapua Palma 308 WIN case.

Roy

By: Emil Praslick

Emil Praslick — Mon, 28 Mar 2011 20:42:46 +0000

So what was this test, exactly? How the picture of a spark differed? More meaningful data might include velocity es/sd changes between the two cases, as well as pressure data.