chasing a wildcat 6.5 gt

R

rsmithsr

Well-known member
there is today a cartridge called 6gt. the results of tom at vapor trail bullets and george at GAprecision. they started with the 6.5 x47, shortened and necked down to 6mm. designed for prs( i think) it is a bit bigger than the dasher. dies, reamers and brass are all available commercially. i read where a guy in the east won his state 1k br championship with a 6 gt this year.
tom had a thought of opening it back up to 6,5 and see what happens. his rifle has been around for a while. he shot it in the 2021 1k ibs nationals, which is where i first heard of it. it seems to me that it might make a windy day 600 yd rifle when shooting against dashers.
being the foolish person i am, i bought 500 pcs of new brass, and started designing and buying parts and pcs.
the 6.5 gt brass is simple, neck up to 6.5 and turn to match your reamer.
powder has been a big issue for several years, and i started buying 4 or more lbs of anything
that came on the market. varget 4895 (imr h even accurate 2495) reloder 15.5.
i have primers, both 205 and 205m with cci 450's and some russian.
bought a mid weight 30" blank from lester, had jgs do the reamer, and GO precision did the chambering.
stock is a kelby 1k, with a 12-42 nf for now, jewell trigger.
 
my plan was to shoot vapor trail 139's but there has been very few 6.5 jackets on the market.
again i went on a buying spree, anything 140 and down in 6.5. my initial thinking was that even a quality production bullet might work at 600 yards.
i tried hornady 140 eldms to start and was not getting the velocity i wanted with Imr 4895. i switched to rl15.5 and things looked better but still too slow.
i changed to JLK 130 VLDS with the 15.5. i was able to exceed 2900 fps.
currently at 37.x at 2895 fps and under .1 at 100.
time for some fine tuning and then maybe a match.
 
dies are sort of an issue,,,but should not be...
it is just a necked up 6gt and there are production 6gt dies on the market.

i made my first seater by lapping a 6.5x47 that i had shortened. it works but not sure it is br quality.
i found a rcbs 6.5x47 seater and a rcbs 6gt seater. by swapping the guts i have threaded 6,5 gt seater,
bushing sizer was simple. i reamed the neck section of a rcbs bushing die to .295, dropped in a 6.5 neck bushing and all is well.
i am currently working with l.e wilson on modifying a 6gt seater to a 6.5 gt seater.
 
so a big jump forward. over 200 rounds thru the number 1 rifle(described above). dies are complete. a used early LRB stock was found and reworked. got a borden brm and a 1.25 30" bbl chambered by GO again. it is all together and i have gone from rifle 1 onto rifle number 2. i had little luck in load development so i took the best load and retested with 4 diff primers. in the end the ccibr4 did the best. with fire formed match brass i have closed in a good load. today i verified the load, i shot loads at .002 depth on either side of the prior best and shot down a tenth, so the seating depth confirmed the best. one shot 0.217 and the powder decrease shot 0.174, both appear to support the 0.099 shot with 38 gr and .015 off the lands somewhere around 2975.
i have a lighter bbl on order but may hold on to it. the current rifle is right at 20 lbs and light gun legal.
 
alot of load development in the prototype and now some proof in the almost real gun.
shot small groups today to proof the best loads..( a .306 and a .167!)
ready for a 600 yd match...lol there are none nearby till OJAI gets their roads repaired.
 
so here is a small update. it took 14 plus months to get a custom krieger bbl. gary ocock chambered it for me and i put ti together this week. no shooting yet as i have the 1k nationals next weekend. when i get back i;ll do some work and see if it will do what the heavy bbl did. ojai is back up and running!
 
so a jump sideways...to h4895 powder. i am over 2900 fps with the 130 jlk vld. did a short ladder to see velocities and then picked three and shot them this am. best 3 shot group at 100 was a 0.155, this was touching the lands..my normal starting point. i will load some on either side and go shorter...-.005, .010, -.015, -.020. the last bbl shot best at -.015 and most have shot well in the -.010/ -.012 range . may shoot tomorrow am
 
stepping forward some more testing, loads hitting .25 or so and started fine tuning. yesterday in some wind i did more fine tuning... with a known load i went touch(000) , .003 off, .005 off and .007 off..all based on best groups from 000 and 5 off, 10 off did not do well. in the end. h4895 at 36.2, and .007 off shot right at 0.250 in the wind.
done! well i go proof it but it had been consistent. less than 60 rounds fired to produce a competitive load!
 
this week i had a 4"x8" front end made for the rifle. the rifle as built was a laminated wood stock with the width at about 3.75..which was a pain as my other guns are 4". it also was a flat fore end, which tended to rock on the center of the bag. i had the 4x8x .5 plate milled thru the center to produce 1/2" rails with a raised center to prevent bag contact. hopefully this will help a bit .
 

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I've experimented with sleds quite a bit. The biggest problem with them is stability gained in width is usually offset by the gain in height giving some advantage back to the gun.

The higher the bore off the bag the more it's leveraged by barrel torque.

Take 1/2" material off the bottom of the stock fore end or more then install the sled and you seriously improve stability and tracking.

I've got a Panda with a 6" sled mounted up into the front of a laminate LRB that's shot some of my best aggs to date.
Curt Knit runs wider lower fore end stocks and is very tough to beat.
 
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Panda pics
 

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i think mine is close to the lrb's i currently have. if you want low look at the current stocks by alex. i have stayed at 4" by choice, this rifle came with a 5" which i took off.
on a side note i am currently at 16.95 lbs with the lens cover! built for the lite/17lb class. my other bbl is a straight that makes the rifle over 19
 
Yeah I've got one of Alex's 4" low stocks on a Bat B as well. Shoots/tracks extremely well.

The 4" is a very good platform all I'm saying is there's a lot of benefits in getting lower.
 
i did not mention it but i am sure several of you had thought about it. adding a chunk of al to the front of the stock change the harmonics and shooting went to schitt. vertical added. so now i need to do some mini load testing to reduce the problem. i am at the top end so need to tune down and see what happens. today i shot both the best load and the same load down a 1/10 gr and both had vertical.. may need to do some shooting to settle the rest to the new( normal for the other rifle shot off this rest). krappolla
 
so some good news today. went to the range with 3x of each from 36 down to 35.6. could not go up in charge as i was at a top load in this bullet/powder combination. the good was 35.6 shot .200. with 35.7 at .257. will try to confirm and then maybe do a primer test with the final load. the bad news is the velocity is not where i wanted...just a little low 2880 was at 2950
 
2880 +/- has almost always been a wider more forgiving node than the faster stuff in my guns.
I always look all the way up through 2900 but usually wind up <2900
 
so today i took a drive to payson to shoot a couple of shots. 2 foulers and then a 5 shot group. i made the trip as the weather was suppose to be very mild..like 1 mph wind.
i took the 2 fouling shots and was amazed. that measures 0.037 for 2 shots, first is cold clean bbl then a follow up.
dang that is nice
 

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the five shot group to prove the load was .4, but i blame it on me and the wind.
velocity was right at 2900.. so gonna load up some and go to a 600 yd match sept 15.
 
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