.243 wssm

[RLH]

a friend came by last night with a new model 70 in 243 wssm. wierd lookin' cartridge. feeds horribly too. too fat and too short. ballistics on paper are real impressive. anyway, the rifle is brand new. it's a model 70 but it's the push feed style instead of the controlled round feed system. all black synthetic stock, matte finish blueing. don't know if it is a particular model or style. didn't see anything on it to indicate that. he shot the rifle twice. 100 gr winchester factory loads. both rounds jammed the action. could barely get the bolt back open. the spent cases show some pretty severe pressures. flat primers and real deep firing pin impressions. and if you dropped one of the shot cases into the chamber, the exctractor wouldn't engage the head. should just pop right over the rim. it chambers unfired rounds ok, other than the round is so short and fat that the action doesn't work worth a damn, but once you get it going down the barrel, the bolt closed ok and it ejected them properly. couldn't get it too feed worth anything from the magazine. really dissapointed in that. anyway, what might be the cause this high pressure indication? don't really think it'd be bad loads. i mean it could be, but i've never really heard of anything like that. head space seems to be ok in that there is some resistance when you close the bolt, like the shoulder is seating up as it should. he said he had a heck of a time getting the shot rounds extracted. could the throat maybe be way short causing excess pressure? excessive chamber size? i told him to take it back. anyway, i was sure dissapointed with the performance of the action. i'd been thinking of seriously of buying something in that caliber. never been a fan of the push feeds anyway, but with that fat little cartridge it doesn't work worth a damn. any ideas what his problem might be?

 

[RELH]

There is the possibility that he has a short chamber. Needs to have it checked with a Go and No-go chamber gage to ascertain for sure. If the chamber checks out ok, I would feel that the loads may be to hot based on the indications you observed. This has happen in the past even with factory loads, but it is very rare. There is also a possibilty that he has a rough chamber that is not smooth enought causing the bolt to bind up after firing.
As for the feeding, short fat rounds can be a bear to feed if the proper modifications are not made to the rails, magazine. If the rounds set far back from the chamber ramp, in the magazine, try to position one round in the mag where it sets further forward and see if the bolt will pick it up and feed it. If it does, the magazine guide-carrier may have to be shorten and a block put in the rear of the mag for better feeding. also sometimes the mag guide feed angle can be altered for better feeding. He should send it back to the factory and have them correct the rifle at no cost, and since the ammo was factory, he should send them several of the fired cases, and the rest of the unfired rounds, so that they can examined them for excessive pressure. I have seen the schematic for this round, and I felt it may have problems feeding if the rifle did not have major modifications over the standard rifle. I have seen this before with some military rifles being converted to mags and the original magazine guide had to be altered to allow proper feeding of the fatter cartidge.
RELH

 

[mtmuley]

I am pretty sure I have an article in an old Handloader or Rifle Shooter that adresses this very problem. I am still looking through them but will keep you posted. mtmuley

 

[GJM]

I don't have the 243, but last yr i bought the 223 in a Browning A-Bolt Medallion,the feeding problem was the same as you mentioned would jam every time with a single shell in the magazine, I found if you load it up with the full 3 rounds that it would feed ok with no problems, to me it shot well have smacked alot of yoties and jacks with it. Although I reload to bring it up to factory specs for bullet speed it to showed alot of pressure on the brass with flatened primers and gas leakage. Backed the loads off considerably and it's a sweet shooter, these 2 calibers will go the way of the DODO as they are too much of a hassel for the average shooter.I'll take my 22-250 any day. In short they are toys for boys! had to have one, now for the most part it sets in the gun safe!