Speer TNT 125

I'm looking for some info on OAL for Speer TNT 125 loads for my 300 AAC, can't find any published. I'll be putting them over H110 which I've have good luck with running Hornady 125 SST loads at 18 grains with a 2.10 oal. Speer loads are more for plinking and run n gun. Posted pic is of my SST groups from a 10.5" barrel at 100 yards with a Vortex Sparc Red dot. While this would not suit me for a precision rifle I'm pretty happy for a PD rifle with a red dot with this group. Thanks

 

The following it's a thread I started on exactly the same subject, 300BO, 125gr TNT, H110.

https://www.thehighroad.org/index.p...-300-aac-blackout-and-speer-125gr-tnt.863105/

Hopefully I will have Chrono data to share after this weekend.

 

Chances are with the short fast tapering TnT bullet your not going to have to worry about them even coming close to the lands before they fall out of the case or will they fit in the mag, you biggest worry will be neck tension. I would start off seating a caliber of bullet in the case, make sure they feed and chamber right then go shot them. So seat .308 or so of the bullet in the case. Easiest way to do this is measure from the bullet base up the bullet .308 with your caliper and mark the bullet with a sharpie then seat the bullet in a case until the sharpie mark is just inside the case mouth. Ya it's a little ruff measurement but it's close enough. Anyway this has worked well for me when shooting TnT bullets out of my 308 and 7mm RM.

 

Speer lists a loaded length of 2.060” for that bullet.



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When I was working up my load in the thread I linked to I found that OAL you mention of 2.060 inch seems to put as much bullet into the neck as possible without over inserting below the bottom of the neck. For that stubby little bullet it seems like the best OAL for its use in 300 BO assuming it will feed.

 

Thanks for the help. I saw your ladder test in the link and I'm gonna do one similar. Sounds like a good length, I'll use my Lee factory crimp die likes always.

 

Just seated one of these rounds in a case at 2.060. compared the ogive with one another f my Hornady SST loads at 2.10 and the ogive measurements are within two thousandths of each other. The SST may be seated a slight bit deeper, but I think this oal should be good. I think I'll ladder up with H110 from 17, 17.5, and 18 and see what I get. Thanks

 

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Barman54
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After loading a few of these I did notice some inconsistent ogive lengths that will affect load length and/or seating depth. Same box and batch. Saw this before in other bullets like the Hornady 75 grain bthp.

 

Here are some primer pics of the load I work up to, 18.5 grains H110 at 2.060. can't find any ejector marks or swipes, opinions? I measured some spent primers compared to factory, they were about three thousandths wider.