Longshot 10 mm loads

[bigarm]

I would like to try some Longshot that I just got with my 200 grain powder coated cast bullets for 10 mm. Hodgden has only fmj load for 200 grain with a starting load of 7.0 grains and max load of 8.2 grains. Where should I start for cast bullets?

 

[Dudedog]

I don't own a 10mm but in general and that is a big general I would back off 10% from the starting jacketed load and work up from there if no else has any info.

 

[KansasSasquatch]

From what I gather powder coated bullets can be pushed to FMJ velocity without any negative effects. But lead doesn't need as much powder to hit those velocities. So backing off 10% of 7.0gr (6.3gr) probably isn't a bad idea. But then my experience with Longshot tells me that it works best on the upper end. So if I were in your situation I'd probably start at 6.5gr. But that's me. I have no experience with 10mm nor powder coated bullets. I'm not suggesting you start at 6.5gr, just explaining why I'd start there.

 

[Rule3]

I would just use the start load of 7.0 gr. Powder coated or Hi Tec coated can withstand pretty much what plated can if not more.

 

[OilyPablo]

All I have ever loaded 10mm with is Longshot. I can tell you people (say maybe at a certain 10mm site) go over book with regularity. I am NOT recommending this in any way, shape or form, I'm just saying starting at 7 grains would not produce any over pressure. You don't say what gun, but 6.5gr would be very conservative, most likely would produce some decent plinking rounds but may be a little weak for some AR carbines and Glocks with 20#+ springs. Most likely would function with stock Glock springs and S&W 1006, and most 10mm 1911's.

 

[bigarm]

I made a few rounds at 6.8 grains and they seemed okay. So I then made about 11-12 rounds at 6.8, 7.0 and 7.2 grains. Hopefully the rain will let up tomorrow and I can get out the chronograph and see where we are at.

 

[Ex]

HUGE plus 1 to longShot in 10mm.

My best accuracy has been at about 2/3rds to 3/4s of the recipe for a given weight.
Clean burning and good velocity.

 

[bigarm]

I loaded rounds at 6.8, 7.0 and 7.2 grains of Longshot. 7.2 gave me average velocity of 1043, extreme spread of 61 and s.d. of 21. I then upped it to 7.5 and got 1066 average velocity, 43 extreme spread and 14 standard deviation. I didn't gain a lot of velocity by going up but did lower the extreme spread and standard deviation. All brass looked fine . I think I will stay there for awhile. It was a fairly pleasant load. That was a power factor of 213. I did not test for accuracy, but the higher loads seemed to shoot to point of aim better than the lower loads.