Reloading 350 Legend with Lil Gun

[SEGAM]

Hello everyone.

New to the site and kinda new to reloading. I’ve been reloading for almost 3 years. I primarily load for 308 and 243, and recently 350L, but mainly 308. 5% for hunting loads, the other 95% for 308 match bullets, which are just for fun. In those 3 years I’ve reloaded 4k+ loads, by far most of them being 168SMK’s. I bought the 350 just to have an off the wall fun cartridge to play with.

I thought I had a good understanding of reloading, but the 350 threw me a curve ball that’s got me concerned.

I shot 170 TSX and 165 FTX on top of H110 first with decent results (maybe 75 rounds). I bought a box of 170gr Hornady SP Interock bullets and a pound of Lil Gun. I started with 27.3gr (Hodgdon states 27 start/27.9 max). The reason for starting above max is, from my understanding when you load long you get extra volume to play with. This has never been an issue before with bottle neck cartridges. In fact, I’ve gone more than a grain above max on a few powders with no pressure signs. This load was STUPID hot. My chrono read 2450fps! Bolt stuck, primer blew out..this is a first for me. Even at min load of 27gr, I’m overly confident that this woulda been way too hot. I pulled the other 14 bullets I had loaded and weighed the charges and all were correct. Now I’m unsure about where to start my charge weight. Here are my specifics.

Win case trimmed to 1.706
CCI SR 400 primer
27.3 Lil Gun
Jammed BTO-1.895
Loaded BTO -1.834
No crimp

Any help or suggestions much appreciated

 

[357Max]

What gun? Assuming AR. Barrel length? Gas system length? Bullet used by n the hot load was 170 SP interlock or 170 TSX? Confirm bullet used was .355 & not .358?

I haven’t tried Lil gun, SBR So-com powder works great in the 350L 165-180gr bullets.

 

[SEGAM]

What gun? Assuming AR. Barrel length? Gas system length? Bullet used by n the hot load was 170 SP interlock or 170 TSX? Confirm bullet used was .355 & not .358?

I haven’t tried Lil gun, SBR So-com powder works great in the 350L 165-180gr bullets.

No it is a Win Stealth XPR 16.5” barrel with a 16 twist. The hot load was the Hornady SP Interlock at .355”.

 

[357Max]

No it is a Win Stealth XPR 16.5” barrel with a 16 twist. The hot load was the Hornady SP Interlock at .355”.

I haven't had my hands on any of those interlock's. Is that the specific bullet your load data had listed?
If the interlocks have more bearing surface, that could spike pressure with fast for caliber powders. You could just have a hot or dry can of lilgun also.
I've gotten a hotter than normal lot of XBR before with similar results to yours. I'd drop a full 1.5 grain min if your wanting to stick with that powder.

Lil Gun is on the fast end of the spectrum for 350L with over 147gr IMO. CFE Black or SBR Socom is a better fit for 160+gr.

 

[SEGAM]

I haven't had my hands on any of those interlock's. Is that the specific bullet your load data had listed?
If the interlocks have more bearing surface, that could spike pressure with fast for caliber powders. You could just have a hot or dry can of lilgun also.
I've gotten a hotter than normal lot of XBR before with similar results to yours. I'd drop a full 1.5 grain min if your wanting to stick with that powder.

Lil Gun is on the fast end of the spectrum for 350L with over 147gr IMO. CFE Black or SBR Socom is a better fit for 160+gr.

I was wandering myself if that was the correct bullet, but fairly certain it is. Hodgdon just says Hornady 170 SP, doesn’t say Interlock. I tried searching just 170 SP, and every result on every website brought up the Interlock, so leads me to believe that’s it.

I definitely have no problem swapping powders and will. I wanted to try LG just because of the advertised velocity. With it not being a very impressive cartridge ballistically, I wanted to get the best velocity as possible. I may bump it down a couple grains just to see what happens, but I’ve got some lighter fmj’s I’ll use it on for sighters and plinking and such (starting a lil low on the charge, of course).

Something I found interesting is that Hodgdon gives the 165 FTX a 2.9gr window from min to max charge. The 180 PP gets 2.5gr from min to max. The 170 Interlock is only a .9gr window. Seems odd.

Thank you for the input! I’ll definitely try out the powders you suggested and see what kind of groups I can get. Any time I can get in trouble with the lady by buying more components is an adventure!

 

[Shaky Trigger Finger]

I don't personally have any experience with lil gun but on another group I belong to it is often mentioned that Lil gun is VERY temperature sensitive in the 350 Legend. The general thinking is there are many good powders for this cartridge and Lil gun isn't worth the potential trouble. I load with IMR 4227 and H-110 with good results

 

[BLEE]

GRT says that a 350L, 170gr Interlocks @ 27.3gr Lil Gun, is at 63,144psi, exceeding max pressure of 62,366psi. I'd drop the load down to 26gr and work up in .1gr increments to find the happy place for that rifle.

 

[SEGAM]

Well guys I done did it again! Finally got some time to mess with the 350L again and blew another primer.

This go around I backed the charge down to 24.8gr (27 is Hodgdon’s minimum) of LG and was gonna work up .3gr for each group. As you can see, I didn’t make it far at all…first shot got me. I pulled the bullet on a few others just to make sure I didn’t measure wrong, and they were all within .1 of what I loaded. I’m baffled..

I’m seating the bullet around .080 longer than Hodgdon’s OAL, but still .060 off of the lands. Maybe that’s it? I’ve gone that much on bottleneck cartridges and never blown a primer.

In my creek bottom, shots over 100yds are rare, so I don’t really need to sweat velocity anyways. Just figured there’s no point in not getting another 100fps if it’s there to get..

I appreciate y’all’s input and if you have any more, I’m all ears. I may tinker with it a bit more, but a different powder is definitely happening on the next go around.. again, thanks for the feedback.

 

[357Max]

View attachment 8259998
Well guys I done did it again! Finally got some time to mess with the 350L again and blew another primer.

This go around I backed the charge down to 24.8gr (27 is Hodgdon’s minimum) of LG and was gonna work up .3gr for each group. As you can see, I didn’t make it far at all…first shot got me. I pulled the bullet on a few others just to make sure I didn’t measure wrong, and they were all within .1 of what I loaded. I’m baffled..

I’m seating the bullet around .080 longer than Hodgdon’s OAL, but still .060 off of the lands. Maybe that’s it? I’ve gone that much on bottleneck cartridges and never blown a primer.

In my creek bottom, shots over 100yds are rare, so I don’t really need to sweat velocity anyways. Just figured there’s no point in not getting another 100fps if it’s there to get..

I appreciate y’all’s input and if you have any more, I’m all ears. I may tinker with it a bit more, but a different powder is definitely happening on the next go around.. again, thanks for the feedback.

Well your using good brass. The Winchester is thickest at the bottom of all available options. Also consequently the lowest case volume.

I haven't done a ton of load workup on the 350L yet, but I did a lot of research before I started. As a result I started with Shooters World SBR Socom. It burns clean & with a basically full Winchester case 29.2gr & 165 FTX it duplicated the factor Hornady load. In the Hornady case with 29.5gr it was just 10fps faster, both loads had no pressure signs. 2185-2195fps from an 11" barrel.

I have no idea how temp sensative this powder is, but I suspect it's better than some of the other popular options.

It was in stock at Bruno's a week ago.