Ammo jams in a Rem. 243 Win. semi-auto.

The Burro · June 26, 2009, 11:38 PM

I have a persistent problem with ammunition jams with a 1970's vintage Remington semi-auto in 243 Win. It has been serviced by a gunsmith, but both reloads and store bought ammo cannot be depended upon to cycle without some jams.Current reloads are from Lyman recipe using full sized Lee dye set, 105 gr. Hornady A-Max bullets, 35.2 gr. IMR 4350 powder & Remington 9 1/2 lge rifle primers. Someone has suggested going to a small base sizer die for reloads and I'm seeking advice from someone who has dealt with and overcome this problem. Magazines are relatively new, so I'm assuming that they are not the problem? Any suggestions are welcome. Thanks, The Burro

Csspecs · June 27, 2009, 12:23 AM

Give a detailed description of the jams that you are having. That could help, if they are mostly the same thing.

Seedtick · June 27, 2009, 05:23 AM

I own and load for a Remington Model 742 (got it new back in 1980) in .243 although I've not shot it in several years. I never had any trouble with factory ammo but I had to switch to a small base full length sizing die to get it to completely return to battery. I would recommend that you get yours to work reliably with factory stuff and that fix might also take care of the reloads. Do you have a new/unaltered Remington factory magazine? I bought a non-factory mag and I never did make it work right.

I picked up some ballistic tips and I'm gonna load some up and shoot my old .243 some in the near future.

ST

James R. Burke · June 28, 2009, 06:54 AM

I had a differernt caliber that I had to go to a small base sizer die. That corrected the problem. Not sure if that would do it for you, but it worked for my .308 at the time.

T. O'Heir · June 28, 2009, 09:18 PM

35.2 gr. of IMR 4350 is under minimum for a 105 grain bullet according to Hodgdon. 36.7 to 40.2. H4350 starts at 35.0 grains. The two powders are close, but not the same. However, because it's not happening with just your reloads, that's not likely to be the cause. Something in the rifle is the cause. Most likely the mag. The lips may be bent in a tick. Long, fine, needle nosed pliers will fix that.
How is it jamming? If, for example, the cartridge isn't coming out of the mag and into the chamber, it's the mag. Jams are caused by the ammo or the mag, most of the time.
Full length resizing every time is required for any semi-auto. Either a regular FL die or a Small base die. Your FL die is fine. If you do opt to buy an SB sizer die, you'll only have to buy that one die, not a whole set. Since it happens with factory ammo too, I doubt it'll make any difference though.

snuffy · June 28, 2009, 10:37 PM

Failure to go completely into battery,(the bolt locking lugs NOT rotating all the way closed), is caused by a dirty chamber. Since you are having this problem with factory loads, it isn't a sizing issue. But, since you didn't go into detail about just where the jam occurs, I'm/we're just guessing. Did the gunsmith pull the barrel, then polish the chamber? I bet he didn't, just gave it a swipe with a chamber brush.

When I worked in a gunshop that specialized in 740, 748, 7400 rem rifles, every one had the barrel pulled, then the chamber was polished with a high speed ¼ inch drill spinning an old 30 cal brush wrapped with 4-0 steel wool. Problem rifles that had chronic jamming, ran great for several years, or until the chamber got rusty or fouled.

The Burro · June 29, 2009, 10:43 AM

Thanks for the imput...The "jam" normally manifests by the round not entering the breach properly before it is slammed forward...generally the bullet tip is slightly dinged as a result. No, I'm sure that the gunsmith did not remove and polish the barrel based on the charge for the "repair". He says that he ran 10 rounds through when He was finished and had no problems, however.
Once ammo becomes available again, I might try a few different suppliers to see if any of them work OK, then proceed back to alterations on my reloading dies, recipes, etc. and/or find another gunsmith to do a more detailed repair.

June 26, 2009, 11:38 PM	#1
The Burro Junior Member Join Date: January 16, 2009 Location: No. California Posts: 4	Ammo jams in a Rem. 243 Win. semi-auto. I have a persistent problem with ammunition jams with a 1970's vintage Remington semi-auto in 243 Win. It has been serviced by a gunsmith, but both reloads and store bought ammo cannot be depended upon to cycle without some jams.Current reloads are from Lyman recipe using full sized Lee dye set, 105 gr. Hornady A-Max bullets, 35.2 gr. IMR 4350 powder & Remington 9 1/2 lge rifle primers. Someone has suggested going to a small base sizer die for reloads and I'm seeking advice from someone who has dealt with and overcome this problem. Magazines are relatively new, so I'm assuming that they are not the problem? Any suggestions are welcome. Thanks, The Burro __________________ The Burro

June 28, 2009, 09:18 PM	#5
T. O'Heir Senior Member Join Date: February 13, 2002 Location: Canada Posts: 12,453	35.2 gr. of IMR 4350 is under minimum for a 105 grain bullet according to Hodgdon. 36.7 to 40.2. H4350 starts at 35.0 grains. The two powders are close, but not the same. However, because it's not happening with just your reloads, that's not likely to be the cause. Something in the rifle is the cause. Most likely the mag. The lips may be bent in a tick. Long, fine, needle nosed pliers will fix that. How is it jamming? If, for example, the cartridge isn't coming out of the mag and into the chamber, it's the mag. Jams are caused by the ammo or the mag, most of the time. Full length resizing every time is required for any semi-auto. Either a regular FL die or a Small base die. Your FL die is fine. If you do opt to buy an SB sizer die, you'll only have to buy that one die, not a whole set. Since it happens with factory ammo too, I doubt it'll make any difference though. __________________ Spelling and grammar count!

June 28, 2009, 10:37 PM	#6
snuffy Senior Member Join Date: May 20, 2001 Location: Oshkosh wi. Posts: 3,055	Failure to go completely into battery,(the bolt locking lugs NOT rotating all the way closed), is caused by a dirty chamber. Since you are having this problem with factory loads, it isn't a sizing issue. But, since you didn't go into detail about just where the jam occurs, I'm/we're just guessing. Did the gunsmith pull the barrel, then polish the chamber? I bet he didn't, just gave it a swipe with a chamber brush. When I worked in a gunshop that specialized in 740, 748, 7400 rem rifles, every one had the barrel pulled, then the chamber was polished with a high speed ¼ inch drill spinning an old 30 cal brush wrapped with 4-0 steel wool. Problem rifles that had chronic jamming, ran great for several years, or until the chamber got rusty or fouled. __________________ The more people I meet, the more I love my dog They're going to get their butts kicked over there this election. How come people can't spell and use words correctly?

June 29, 2009, 10:43 AM	#7
The Burro Junior Member Join Date: January 16, 2009 Location: No. California Posts: 4	243 Ammo Jams Thanks for the imput...The "jam" normally manifests by the round not entering the breach properly before it is slammed forward...generally the bullet tip is slightly dinged as a result. No, I'm sure that the gunsmith did not remove and polish the barrel based on the charge for the "repair". He says that he ran 10 rounds through when He was finished and had no problems, however. Once ammo becomes available again, I might try a few different suppliers to see if any of them work OK, then proceed back to alterations on my reloading dies, recipes, etc. and/or find another gunsmith to do a more detailed repair. __________________ The Burro

June 27, 2009, 12:23 AM	#2
Csspecs Senior Member Join Date: December 21, 2005 Posts: 1,111	Give a detailed description of the jams that you are having. That could help, if they are mostly the same thing.

June 27, 2009, 05:23 AM	#3
Seedtick Member Join Date: June 11, 2009 Location: Central Arkansas Posts: 45	I own and load for a Remington Model 742 (got it new back in 1980) in .243 although I've not shot it in several years. I never had any trouble with factory ammo but I had to switch to a small base full length sizing die to get it to completely return to battery. I would recommend that you get yours to work reliably with factory stuff and that fix might also take care of the reloads. Do you have a new/unaltered Remington factory magazine? I bought a non-factory mag and I never did make it work right. I picked up some ballistic tips and I'm gonna load some up and shoot my old .243 some in the near future. ST

June 28, 2009, 06:54 AM	#4
James R. Burke Senior Member Join Date: January 3, 2009 Location: U.P. of Mich/Quinnesec Posts: 1,897	I had a differernt caliber that I had to go to a small base sizer die. That corrected the problem. Not sure if that would do it for you, but it worked for my .308 at the time.