m1917 Eddystone Bedding: Muzle Pressure?

[gc1054]

Currently "rejuvinating" an Eddystone M1917 for use in CMP vintage matches. Rifle is in military configuration (stock, etc.) & was re-barreled at some point with HS 6-44 barrel. Basic stock beddng looks good with no contact in barrel channel with no interference up to muzzle bed. Current muzzle pressure is 1.7-2lb. What is the suggested starting muzzle pressure (or arsenal specified range) for the M1917? Thanks!

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[WarPig1976]

1.7-2lb.

We talked of this a while back. Seems your right in the ballpark. I have an unissued Eddystone that comes in right around 2lbs.

[gc1054]

Thanks! I'll leave it as is for now and see how it groups.

[mausernut]

Let us know how it groups

[ed skeels]

I am sure you know that bedding (Devcon/MarineTex etc), rear shims, are a no no on CMP "Game's" rifles.
As issued they say in the rule book.
But one probably could be creative. Sorta like NASCAR.
Hope it hammers!
Get it done in time for Creedmoor East.

Ed

[RC20]

I think the it is a violation per match rules to put specific shims etc to achieve barrel pressure.

I have read its not enforced in a lot of cases but that is my understanding of the rule itself.

Anything suable that achieves that will likely be overlooked but anything overt may be tagged.

I don't know what penalty is other than out of that match.

[Patrick Chadwick]

I think the it is a violation per match rules to put specific shims etc to achieve barrel pressure.

So what is one supposed to do? Bend the barrel?

Seriously, if a certain pressure range was specified in manufacture, then it would sometimes have been necessary for an armorer or arsenal to make corrections to a rifle that had gone out of spec. By restoring the bedding. How else?

Whatever an armorer would have been permitted to do in the past to keep the rifle in spec cannot be construed as improper alteration of the weapon, except, perhaps, by someone living on a cloud well away from the reality of weapons maintenance and refurbishment.

Here is a more realistic ruling from the world of muzzleloaders (MLAIC):

Rifles such as the P1853 and P1858 (3-band and 2-band) Enfield Rifle muskets (as they were termed at the time) were bedded, in the sense that the stock was carefully shaved in the barrel channel to provide a good fit. No doubt the same was done for other types of rifle. If the barrel loosened or the stock warped, the rifle was not thrown away as unserviceable, but judicious scraping and/or insertion of veneer shims was used to restore the bedding. After a century and a half it may be assumed that, as a result of wood shrinkage and warping, many, probably the majority of rifles no longer have the same good fit as when they left the arsenal. So it is considered OK to restore the bedding, using materials that would have been available to an armorer of the time. That means wood, cork or paper shims, animal or casein glue, but no plastics or epoxies. The general aim is to keep to the spirit of the original.

The same ought to apply to the competition you mentioned. Doing what an armorer of the time would have done to keep the rifle within spec, and using the same materials that he would have had available is proper maintenance, not cheating!

[gc1054]

Finally got out to the range yesterday afternoon and ran a box of Hornady 168gr AMAX through the Eddystone. Setup on a SR1 target at 100 yds & two sets of 10 shots yielded 96-3x & 95-2x . Was shooting prone off a sandbag with mild but gusty crosswind. Checked muzzle pressure before and after each 10 round set using a Lyman trigger pull meter and noted that the muzzle bearing pressure decreased after each set of shots (went from 2 to less than 1lb). So something is changing the muzzle pressure as the barrel & breech heat during firing. Action screws did not move and were torqued before shooting. Plan to disassemble the rifle and check again for clearances in the barrel channel or evidence of rubs.

[Patrick Chadwick]

noted that the muzzle bearing pressure decreased after each set of shots (went from 2 to less than 1lb). So something is changing the muzzle pressure as the barrel & breech heat during firing.

You have a wood-metal "bimetallic strip". The metal is bearing on the wood, and heats up faster. As long as the bearing pressure remains in the useful range, the effect on grouping will be small. BTW, don't forget to support the rifle on your hand on the sandbag, in the position your hand would be if you were using a sling, if you want to get results with the same POI for freehand shooting.

[gc1054]

Thanks. I'll post another range report with the results with higher muzzle bearing pressure. Will also re-check the muzzle weight after the 10 shot groups as done previously