Problems with gas checks for the Lyman 300136 mold for 7.35x51 M38 Carcano

  • 1.3K Views
  • Last Post 03 October 2015
sansarc posted this 01 October 2015

This is the strangest method of posting I have yet encountered, cannot cut and paste, so will give up.

Attached Files

Order By: Standard | Newest | Votes
barra posted this 02 October 2015

I have a double in that mould but no gun to shoot it in. have tried pp ing it for 30 cal thou. One on the left.

Attached Files

sansarc posted this 02 October 2015

That paper patching looks good. I have PP for black powder rifles, but never for smokeless. I will try again to C&P what I came up with, tried before but paragraphs get scrambled all over the place.

  Same result, scrambled and mixed up. I have tried several of the most recommended methods, and found them all wanting.  Got to thinking outside the box and came up with a simple yet very effective solution.   The 300136 gas check shank OD measures .250” for the bullet and the .308” caliber gas check is made for a .275” OD shank. I read about annealing GC and the use of instant glue, but gave up on that.  Also read about the magic of using sized down .308” cast bullets, using different .308” bullets, found this all but wiped out the lube grooves and the larger bullet noses would not engrave into rifling, but seated the bullets too deep (I don't care for GC and lube grooves seated deeper than neck/shoulder junction) into case.

Then tried the .284” OD 7 mm GC, which, is made for a .250” OD GC shank, but once installed, the .284” OD remained true and was a smaller diameter than bullet bands, this exposes the rear band outer edges to hot gases. I have also read numerous stories about the 7mm GC use for 7.35x51 causing key holing.   First tried a .308” GC over 7 mm GC,  the .284” OD was too much, requiring a lot of force to size even in a large arbor press and resulting in GC distortion.  Checked a 6.5 mm GC, inside ID was .250” and OD was .275”, looking good. Installed the 6.5 mm GC, followed by the .308” GC over that one, It worked like a breeze to seat both GCs tight through die in the lubrisizer.  Ran several, the GCs and bands all miked out at .302” OD.   style="BACKGROUND-COLOR: #fafafa"So, one just has to use a 6.5 mm GC with the .308” GC over it, or two GCs instead of one.

Attached Files

barra posted this 03 October 2015

looks like a lot of work to me. Have you thought about making your own checks. simple and effective ones can be made too work quite well. look over at cast boolits. Save a lot of hastle I think. 11 0r 12 thou stock of alu or flashing material. I don't do gas checks often as they give me the irrits.

Attached Files

sansarc posted this 03 October 2015

barra wrote: looks like a lot of work to me. Have you thought about making your own checks. simple and effective ones can be made too work quite well. look over at cast boolits. Save a lot of hastle I think. 11 0r 12 thou stock of alu or flashing material. I don't do gas checks often as they give me the irrits. It took a bit of thought and labor to arrive at a very simple effective solution.  But not quite sure what is a lot of work about placing one GC over another one and running boolit through a lubrisizer?   But to each their own I guess.   I have been a member over at Cast Boolits for quite sometime.  

Attached Files

Categories
Search
Popular Tags
This Weeks High Earners
Hot Topics
Close