TargetTalk

I have a P240 .38 with a red dot mounted on the slide. What is a SAFE load to function this without damaging the barrel. I am up to 2.9 BE HBWC and it stove pipes. If I take the dot off it functions great. Thanks

Thats a pretty heavy load for .38.

From what I hear they have tight easily bulged barrels.

Just take the dot sight off, or get an off-slide mount.

and the P240 barrels for .38Special are 'tight' needing .356" or even .355" projectiles.

Be careful with hot loads in the P240, you might get skirt separation. The bore dimentions are :Bore diameter (between the lands) .3425"+.002, Groove diameter.352" +.002, these dimentions make 38spl bullets that are sized .357-.358 tight.
My load for my P240 using HBWC is 2.5gr of Bullseye with never a malfunction and very accurate.
This spring I am going to start casting for my P240 using a custom Hensley & Gibbs mould #251 sized at .354".
Your red dot sight is to heavy for the slide to cycle properly. That is probably why you got the stove pipe malfunction.

I have been shooting P-240's in .38 WC for close to 30 years. Groove diameters run about .355 as do the barrels in the S&W M-52. Hammerli and S&W determined that barrels that have a groove diameter of .355 are more accurate with swagded .357/.358 bullets. Shoot .357 diameter bullets as they intended, they are more accurate. Hammerli P-240 barrels are stout with thick walls compared to S&W M-52 barrels or even .45 ACP barrels. I am sure the bulging stories are from squibb loads a (bore obstruction), not because of a .355 groove diameter. By the way, I have measured M-52 bore on a Zeiss CMM (coordinate measuring machine), .355 groove diameter. They don't bulge barrels either.
Gort

Most of the blown barrels in P240's were caused by blown skirts from HBWC.
The pistol was used a lot in australia for our unrestricted service match. To shoot out to 50yds a hotter load was needed.
The barrel was a 9mm barrel (.355) so to use it you had to size your projectiles down from .357/.358 to .355/.356.
Some brands of HBWC with thin skirts, if unsized, suffered skirt seperation.
Because of this I only used a cast BNWC 140g sized .355.

The HBWCs need a little more velocity to stabilize them (they're longer). Try some that aren't hollow base. There is no practical limit (for your purpose) to how hot you can load them.

I think all the Colt pistols and kits had a .355 bore. Fat bullets are good!
The only load I ever got to shoot well in my S&W52 and Colt kit gun was 3.2gr. of 700-X and the Speer 148gr. HBWC.

PS I tried Hornady, Speer, and Alberts HWBCs, but the best load was the above. I never once had a skirt seperation in all my testing and competing. The 3.2gr. 700X load is fairly stiff.

Hmmm

So, if I use 2.5 grs of Bullsye behinf H&N or Taipan 148gr HBWC in my P240, would that be asking for trouble?

The Taipan skirts seem to be reasonably thick and the H&N's are plastic-coated - which should stop skirt separation....

Leon wrote:Hmmm

So, if I use 2.5 grs of Bullsye behinf H&N or Taipan 148gr HBWC in my P240, would that be asking for trouble?

The Taipan skirts seem to be reasonably thick and the H&N's are plastic-coated - which should stop skirt separation....

2.5gr of Bullseye seems to be in that grey area where accuracy is 'indifferent'.
With a medium roll crimp, lighter loads (2.2gr Bullseye which will not reliably cycle a P240) and heavier (2.7-2.9 Bullseye) should give much tighter inherent groups.

[/quote]

d heavier (2.7-2.9 Bullseye) should give much tighter inherent groups.[/quote]

Would this be classified as a risky load for a P240 .38 barrel? The projectiles have not been resized to .355 .356.

If you are using HBWC 2.9gr of Bullseye should be the maximum load. The worry is that if you use too hot of a load the skirt would separate and get lodged in the barrel. If this happens and you shoot another shot the barrel will bulge. If you use plain base cast wadcutters you can go hotter. You will enjoy shooting your P240 more if you can get your ammo to shoot accuratly with a light load. I would suggest loading small batches starting with 2.5grains of Bullseye and work up to 2.9grains of Bullseye and see what you and the gun likes.

Leon wrote:Would this be classified as a risky load for a P240 .38 barrel? The projectiles have not been resized to .355 .356.

While I used 2.9 grains of Hercules Bullseye in .38Spl for S&W #52 this load was DEFINITELY 'pokey' but gave excellent groups - the #52 was originally designed for the old loadings giving about 880fps and I do not know how a P240 would handle them. Even for 2.7 of Alliant Bullseye I would work up to this with all due care - your dies and die settings could give different pressures.

Lee used to produce a very simple push-through sizer to bring bullet diameters down to a given size. I don't know if they are still available but if you could locate a sample a machinist could easily make one up in .356" or .355".

Spencer wrote:Lee used to produce a very simple push-through sizer to bring bullet diameters down to a given size.

They still make it. It appears whatever bullet diameter you might want is available, either off the shelf or custom. See: http://leeprecision.com/xcart/Lube-and-Sizing-Kit/

In case you don't get it, you don't need to make your bullets smaller. Fat works better.

Any "bulges" are unrelated to bullet diameter.

Thank You Rover
I have been beating that drum for 20 years. Both S&W M-52 and the Sig-Hammerli P-240 were manufactured with tight bores on purpose. They found them to be More Accurate with groove diameters @ .355, using standard .357/.358 bullets. Sig- Hammerli P-240 shooters think Hammerli was so stupid that they would produce a pistol that would not shoot any factory wadcutter ammunition produced on this planet. For some reason this myth never stated around the M-52, which has the same land and groove dimensions.
Gort

Thanks for the responses. It looks so far that I may have to use a different method to attach the red dot or even use a DEWC. Just had alot of HBWC that I wanted to use. The accuracy has been great but not reliable. Just looking for a load with reliability for a slide mounted red dot.