Today at the Bench.....

[JeffreyDeGraff]

Looks like an Interarms Mark X to me except for that safety.

I was thinking mark x also. The receiver sight screw holes were making me think that. Ive seen thumb safety’s on mark x’s before.


JTD

[Flyeralan]

I have no idea. If I had to guess I have put 7-8 hundred through it and it was used when I purchased it. I learned a hard lesson with this gun. Shooting on a very hot day in July,some year back a ways, had a case rupture and had to pound the bolt open. Got sprayed in the face and it really got my attention. Gunsmith said it all looked ok, but I had him cut a thread and rechamber it and it continued to shoot just as good after. My "learning the hard way" about upper end loads and heat.

[JeffreyDeGraff]

Live and learn. Ive learned many lessons like that.

My first swift started life as a 3/8” grouping rifle. By 2500 rounds it was shooting inch groups. I was very pleased with that performance. Killed many many prairie dogs with it.


JTD

[Harter]

We have a Mk X varminter in 22-250 . It doesn't take upper end loads to run up over pressure in the heat . I bought a 50 pack of the Winchester 45 gr 4000 fps rat exploders and the 9th round with 90 seconds to 2 minutes between shots dropped the primer out . Upon closer inspection 6,7,8 had gas leaks . Hand loads that repeated the events were 3031 and a 55 gr FMJ at about 3600 fps , a down in the middle load way off max load .

I think it has to do with how the Mauser and specifically the 308 length and sub 30 cal heavy barrels shed heat around the chamber . I don't have any test data to back that but the 7&8×57 wouldn't have remained combat rifles from 1895-1957 if it were a common problem there .
I ran a bunch of loads in a short period of time through a Santa Barbara 98 in 358 Win with no issues but the heat of the day was only about 80 degrees . That action was machined OM for a 4" OAL as an action only sale , not in the standard 3.5" Mauser .

It's interesting that you got spray . By WWII the 98 had a gas escape on the front ring and by design most of the gas and debris ended up in the mag well . The bolt shroud , even the slicked up Winchester ish and others , should have deflected whatever made it down the race ways . Unless like me you shoot left handed .......

[Flyeralan]

Thank you all for your input, it does indeed look like it may be a Mark X. I appreciate you taking the time to respond.

[JeffreyDeGraff]

We have a Mk X varminter in 22-250 . It doesn't take upper end loads to run up over pressure in the heat . I bought a 50 pack of the Winchester 45 gr 4000 fps rat exploders and the 9th round with 90 seconds to 2 minutes between shots dropped the primer out . Upon closer inspection 6,7,8 had gas leaks . Hand loads that repeated the events were 3031 and a 55 gr FMJ at about 3600 fps , a down in the middle load way off max load .

I think it has to do with how the Mauser and specifically the 308 length and sub 30 cal heavy barrels shed heat around the chamber . I don't have any test data to back that but the 7&8×57 wouldn't have remained combat rifles from 1895-1957 if it were a common problem there .
I ran a bunch of loads in a short period of time through a Santa Barbara 98 in 358 Win with no issues but the heat of the day was only about 80 degrees . That action was machined OM for a 4" OAL as an action only sale , not in the standard 3.5" Mauser .

It's interesting that you got spray . By WWII the 98 had a gas escape on the front ring and by design most of the gas and debris ended up in the mag well . The bolt shroud , even the slicked up Winchester ish and others , should have deflected whatever made it down the race ways . Unless like me you shoot left handed .......

I don’t think it’s a problem exclusive to Mausers. Ive had similar problems in remingtons Ruger and Winchesters. As the barrel heats up the round in the chamber gets warmer and can raise pressures. The problem gets even worse when a round is left in a warm chamber for any amount of time, before being fired.


JTD

[Harter]

I don’t think it’s a problem exclusive to Mausers. Ive had similar problems in remingtons Ruger and Winchesters. As the barrel heats up the round in the chamber gets warmer and can raise pressures. The problem gets even worse when a round is left in a warm chamber for any amount of time, before being fired.


JTD

I didn't mean to imply it was a Mauser exclusive thing , but that I had seen it more in the 300 Savage/308 case lengths in the Mauser actions . Similar strings in 308 , 7×57 , 257 Roberts , and 06' in Savage 110 , Rem 700 , and Win M70 don't seem to do it to such a degree that I've lost primers . That thing in the Carcano was all on me .

[JeffreyDeGraff]

I didn't mean to imply it was a Mauser exclusive thing , but that I had seen it more in the 300 Savage/308 case lengths in the Mauser actions . Similar strings in 308 , 7×57 , 257 Roberts , and 06' in Savage 110 , Rem 700 , and Win M70 don't seem to do it to such a degree that I've lost primers . That thing in the Carcano was all on me .

Ah ok. Sorry I misunderstood what you were saying.

Ive never lost a primer that way, but I have had some heavy bolt lifts and really flattened primers on loads that were not normally that way. I find it happens more on really fast cartridges, ie 220swift 22-250 etc.


JTD

[JeffreyDeGraff]

I got to the range Saturday and Sunday this past weekend.

Saturday I spent on the 50yd range and shot my Winchester 94 44 mag, Winchester 94 32 special, Marlin 1895G 45-70, M96 krag 30-40, and long barreled Siamese Mauser 45-70. The 44mag got sighted in very easily, it was shooting great. The 32 special shot exceptionally well, sighted in 1/2” high at 50 and is going 2060fps with 170gr Hornady fn and IMR4064. The marlin 45-70 was shooting 400gr Speer FP, and got a .385” group with IMR3031, .768 with RL7, and .783” with AA2015. I was testing velocities in the krag and was able to get 2121fps with IMR4831 and 180gr Sierra RN. The Siamese Mauser was with 325gr FTX, got 3/4” with AA2015 and just over an inch with RL7. The RL7 load was pushing that 325FTX over 2600fps, WOW!

Sunday I worked at 100yds with 243win, 95gr SST W760, nothing to write home about. 6.5 Creedmoor, 140gr SST W760, best group was about 1.5”. 30-06, 180gr Sierra sp RL22, got it under an inch finally and going to test 2 more seating depths. 257 Roberts Ackley Improved, 117gr SST H4831, finally got that combination shooting about 5/8”. And my Swiss K31 7.5x55, Berger 175gr VLD hunting RL17, shot a 3/4” group, now need to test seating depths.

Finally was able to get a bunch accomplished. Now I’ve got some more stuff to load up.


JTD

[Flyeralan]

Wow! What a productive couple of days on the range. Great to see the 257 AI shooting that good. Are you done with that load?