Getting Ready for Deer Season

[Hoot]

Hi guys. Long time no see.

As the title implies, I'm getting ready for northern MN = 150yd or less shots, deer season. Last year I took 123 Amax over AR-Comp loads, but never got a shot from the Grendel, which is my backup rifle. Truth be told, most shots where I go are brushy 50 yds and in, so my primary weapon is my 450 Bushmaster punching 200gr Barnes XPBs. Devastating load and plenty lethal for white tails with that frontal area, but I'm not here to argue that one.

This year, I'm going with 120 TTSX over AR-Comp. Keep in mind that deer season can be 50 degrees or -15, so I like AR-Comp for obvious reasons. Anyway, I only have one box of 50 to play with and still have enough left over for hunting.

For my AA Grendel chamber, 1-fired AA brass holds 36.5gr water and the TTSX hit the lands at 2.315. So I'm looking at 26gr AR-Comp and 2.26 COL, yielding a jump of .055. QL predicts 2587fps from my 24" barrel and results with the 123 Amax came in very close to what QL predicted they would launch at using AR-Comp. FWIW, 26gr at 2.26 COL is very close to the predicted 100% case capacity for that bullet, which IMHO, is always a plus.

Still, being a prudent man, I'll start a grain lower (2500fps QL predicted) and work up. My experiment with 100gr TTSX and AR-Comp led me to the conclusion that AR-Comp is too slow for that weight. Then again, what's not to love about 8208 and the 100gr TTSX if I were going that route? The whitetails grow big up here, hence the decision to go with the 120's.

Should I load for a greater jump?
Anyone tried the 120 TTSX with AR-Comp already?

Thanks,

Hoot

[sneaky one]

Hoot, good to hear from you again. The 120 TTsx is a pokey unit- sooo long for it's wt. yes we both hunt short ranges. Seems the cfe-223 is the best option? Not many seem to have info on Ar comp. Tools sent me a shot - recovered 120TTSX that did not expand as stated, too slow. Probably in the 24-2500 range. This is why I went to lighter wt. copper alloy units--speed helps open them up in dramatic ways. You are better off with the 100 gr. TTSX's., as a box stock option. I'll be using a 95 grn GMX this fall for northern MN deer- it will outdo any 120 bullet out there. Bar none.

[rasp65]

Welcome back Hoot I loaded this bullet 2 years ago for hunting season but I used 29.8 gr of 748 for 2421 fps from my 18"barrel. I only bought 1 box of these so I did not do much development. The OAL was 2.6" which fit in my mag. Using my Powley computer I calculate 26 gr of AR Comp to have a density of 104.6 % and 25 gr 100.6% with a case volume of 35.8 gr of water. Last year I used the 100 TTSX bullets over 30 gr H335 a load I got here from PAallen

[Hoot]

Welcome back Hoot I loaded this bullet 2 years ago for hunting season but I used 29.8 gr of 748 for 2421 fps from my 18"barrel. I only bought 1 box of these so I did not do much development. The OAL was 2.6" which fit in my mag. Using my Powley computer I calculate 26 gr of AR Comp to have a density of 104.6 % and 25 gr 100.6% with a case volume of 35.8 gr of water. Last year I used the 100 TTSX bullets over 30 gr H335 a load I got here from PAallen

2.6 OAL!

Damn, I want some of those mags!

Seriously, is that a typo? Even my c_bass16 style slot-modded mag didn't come close to that. Do you have to mill a groove into the upper for them to slide up out of the mag well, unimpeded? Was that a special chamber with a long leade? I was surprised that my chamber allowed the brass to expand so much that the water capacity went up to 36.5gr. QL states the standard, if one exists, should be 35gr of water. Makes me wonder if Helmut based his caliber database on the sized water capacity as opposed to unsized?

To reitterate the one question from my first post: Is .055 enough jump for these monolythic bullets? Obviously, one way to tell is shoot a few starting low and check for pressure signs as I work up. 26gr in my cases is actually 101% capacity, but with my modded electro-pencil case vibrator, it's amazing how much you can settle out extruded powders. IIRC, I posted about that a while back, when I was more active here. Light buzz while waiting for the powder dispenser to meter out the next charge and "Look Ma, no crunch" when seating.

Hoot

[rasp65]

Hoot Sorry to get you excited but it is a typo. I just had cataract surgery and I can't see all that well yet. Should be 2.26". Barnes recommends a .050" jump so you should be fine there.

[sneaky one]

raspt-u no eye cood make a joak hear- but eye wount- good luck with your schpotter I- ball recovery. Catharacts? At your aged?? Whot gives? Too murch intranet- Purn ? Whats your rasp ager again? You'll reclover just fine. lut meu no wenn ur kan see gouder@=%= seneeky wum ooot., bears yur too nale clipster? thee bond arrowsmither iz too toon suun. shall ei buuk yore seet theere fur yeo!' . Joo kno 2.26 iz da maex for the mage leangthen- hymer -unless une cann tweek thee maegs,( eye bee wurkin oin it nowe-)latters- senakies ouot..

[sneaky one]

Hoot, .030-.50 jump is fine for the mono units. As previously stated- the wt.,-to - length -ratio is the problem, with gaining any muzzle speed . Impact speed means a lot more than most probably think of it. The easiest route is the 100TTSX. I found my own -better way. I watched the h2o jugs get destroyed- many times over, w/ the faster-lighter gmx units. I will move to bal. gel. soon. The mono's only lose 1-2 grns. of wt.=plastic tip,, yet keep plowing onward- better than the 120 cup-core units,, that shed lead, wt. as they do the job---all the while-polluting the meat w/ lead shreds= we probably all ate plenty of lead during our lives-from game meat, shot by the hunt groups. Maybe it's time for the change up==lead free. In 1975 the gasoline went lead free,,,,,lead free units will be a problem for many to accept--but it's only for hunting-target bullets can be whatever is legal in your locale.

[Hoot]

Thanks guys. I already found some great loads for the 100 TTSX, which I misspoke of earlier. I had less than optimum results using AR-Comp and the 100gr NBT, not the TTSX. The 100 TTSX's additional hardness seems to provide just the extra resistance to entering and propelling down the bore, to get AR-Comp cooking into it's sweet zone. Not the best choice for maximum velocity, but I swear, this caliber in longer barrels gets along really well with AR-Comp. Runs very clean as well.

Anyway, looking back over threads, it appears the additional hardness of the TTSX allows lighter weights to not splat out on the surface, so I get the appeal for CXP2 game like white tails. I know my Dad, when he field hunted (>200 yds), loved his .243 tossing 95gr bullets for Maryland (where I grew up) deer. I saw him roll them up like dirty laundry on a dead run with it many times. I have some 120 TTSX loaded and will be leaving for the range in a few minutes, before the spray and pray, soldier wannabes show up around noon, venting their testosterone. I like to be packing it in by then. I'll do a mini-range report on the adventure this evening.

Loads range from 25 to 26.5gr.

Hoot

[egrigsby]

Hello everyone, I'm a Retired Marine and building a 6.5 Grendel upper for my AR Platform. You guys are really technical so if you can tell me in laymans terms I would appreciate it. The following is my project:

AR Platform
Model 1 24" fluted, chrome lined match barrel and bolt
Free floated
Match trigger

I am planning to use Barnes 100 grain TTSX bullets. I would appreciate it if you could give me some loads to work up, and the preferred powder (I've read that the Vihtavouri N530 is great, what is your suggestion?. I read above that .030 - .050 is excellent for jump, please elaborate? Hornady brass or Lapua, which is best to use, I know Lapua is more expensive but is it worth the extra cost? I plan to use this setup for hunting Texas Whitetails (small deer, big horns), would love to hunt with someone in Minnesota! I have alot of experience with the M-16/M-4 as I was an armorer in the Marine Corps, but don't want to waste alot of time and money working up loads for my Grendel, thats why I'm asking for your expertise. Hope to hear from the experts soon. Retired pay doesn't allow wasting available funds!

Best regards,

EARL D. GRIGSBY, JR.
Master Sergeant
U.S. Marine Corps, Retired

[LRRPF52]

Welcome Earl,

The Lapua brass tends to last longer than others. Do you already have the Model 1 Sales 24" barrel/bolt combo. That could make a difference in how your chamber handles different projectiles, maximum COAL being a big question.

J&T Distributing uses an actual Grendel chamber, and many have reported excellent results with their J&T rifles.

If you look through the reloading section, and hunting section, there is a lot of info on different loads for the 100gr TTSX, performance on game, etc.

[Hoot]

Welcome aboard Earl. My 24" barrel threw the 100 TTSX most accurately around 2750fps using new AA brass loaded to 2.25 COL. After firing them once, it shot the them more accurately at 2700fps. Both velocities were the same powder charge, but after one firing, the cases picked up another grain of water, internal capacity. No two chambers are the same, nor how they behave, so I'm not sure you'll be able to fine tune a 100 TTSX to yours without some load work. I'm not sure what effect the chrome lining has upon behavior, but I'd imagine it has some effect. Again, you'll have to sort that out.

Hoot