300 win mag grouping problemsPosted by cullen3402412 on February 21, 2015 at 11:10 pm
Hi there group,
i have a t3 300 win mag that i have been trying custom loads on to get a tighter 100 yard group. I had been shooting federal soft point 180's but i always seemed to have a stringer out of every three shot group. 1st shot always about 2 inches higher then the following two nearly touching below. i had my brother shoot it as well and get the same results. so we have tried nearly 15 handloads and getting the same results with those. is there something else i might be missing here that would consistently throw one round astray? thanks for any suggestions.
tikka t3 lite 300 win mag
vortex viper hst 4-16 x 44
ModeratorFebruary 22, 2015 at 4:31 am292 Bullseyes
Hi I would replace the recoil log for a stainless steel one, torque the screws down to what's recommend (do a search on here has I've forgotten the numbers ) then check to see if the barrel is fully floating .
MemberFebruary 23, 2015 at 4:12 am1 Bullseye
Thanks for the reply Larkin. I did check to verify the barrel was free floating and it appears that it is. i do on the other hand have the stock recoil lug in the rifle. I will give a stainless one a shot and see if that helps me. thanks again
MemberFebruary 23, 2015 at 5:44 am1 Bullseye
I would like to see your results after the new recoil lug.
MemberFebruary 24, 2015 at 12:38 am105 Bullseyes
I shoot a 300wsm and I've had similar patterns many times with the “Lite” barrel, cold bore shot…1/2″ – 3/4″ away from shot 2&3…but 2″ is beyond anything we have gotten in our group of shooters.
Whats your procedure for shooting the group?…are you cold bore shooting each round or launching them with time between each allowing the chamber and barrel to heat up.
Check out the 3 shots in the “heart” on the Deer target to see if its a pattern like yours…this is pretty much the extreme spread I would get shooting my 300wsm from a cold bore and then taking my time for the 2 remaining shots letting the barrel and chamber heat up. I do not get this dramatic POI shift if i'm paying attention to barrel temp…I've mostly experienced this in my 300wsm with hot loads or fast factory ammo.
The rifle is very consistent shooter so I've learned to compensate for this after many range sessions.
The 2 other targets show 3 shot groups firing the same ammo as fast as I can at the same POI…big difference if you don't wait between rounds!
All groups shot with factory 150gr Winchester Silver Tips @ 3300+fps….
MemberFebruary 26, 2015 at 6:46 am21 Bullseyes
If you want the best “factory” ammunition I would direct you to ABM by Brian Litz. He is Berger's ballistics guy and that ammo is said to be the best you can buy, and you would be hard pressed to handload better. If you cant get repeatable groups with his ammo, then you have other problems. With a light rifle and big caliber like the 300 win mag you get significant torque in addition to recoil. If you are shooting groups from a bipod make sure its not on a hard surface. The “bounce” you get off of a hard bench is not just distracting it is a group killer. Also get the hard recoil lug from Mountain tactical.
MemberFebruary 27, 2015 at 11:15 pm1 Bullseye
I would suggest using a clamp on muzzle brake for use during load developing so the gun has optimal accuracy And less recoil. I have one on my 300wm and it's great for just shooting.
MemberMarch 1, 2015 at 3:57 am21 Bullseyes
I use a clamp on muzzel brake on my 30-06 T3 Hunter, and it shrunk my groups a bit. I also use the MT steel recoil lug and torque the bolts to about 35- 45 in lbs (wood stock Hunter). This phenomenon of 2in and 1 out is not uncommon. Honestly it's hard to track down, if first shot is out then it might be tecnique if it's 3rd or 2nd shot then maybe bedding or trigger. If cold barrel or clean barrel then first shot should be the out one.
MemberMarch 5, 2015 at 4:36 am1 Bullseye
thank you all for the help and suggestions. I am awaiting my recoil lug.To answer some of the questions:
Yes i cold shoot the first shot and normally wait a few minutes before shooting another. granted the barrel is still warm when shooting the second and third.
I shoot off a bench with a lead sled with 53 lbs of lead for my tests. (all that weight is a lifesaver after a long day) lol
Dog down, that is exactly what i'm getting. The heart shot is what i'm talking about.
MemberMarch 5, 2015 at 8:03 am105 Bullseyes
I thought thats what you were talking about when I first read your post. I've seen it many times at the range.
I hate to break it to you, but…this seems to be a common problem for the larger 30 cal's with a Lite barrel. From my range test on my personal guns… the larger the caliber the more extreme spread you will get between the cold bore shot and follow up shots with the Lite barrel. I have not experienced this to the same extent with any of the varmint, Tac / CTR rifles i shoot. Its just seems to be a problem with the Lite barrel and the way it heats up with the larger loads…We've test fired 3 shots as fast as we can, and on almost all occasions it gave the best groups in the 308, 30-06 & 300wsm T3 Lite rifles we shoot at the range. Usually a small clover, 2 in the same hole and a 3rd touching with hand loads. I feel this is a more realistic test on rifle accuracy for the field, especially if you hunt. You never have multiple cold bore shots or equal waiting time between shots in the field on a live target. Try speeding up the cycle on your followup shots and i guarantee the groups will shrink. I can usually get 3 good shoots on target in 10-15secs max….
I know your 300 recoils quite a bit but try ditching the lead sled and shoot off a bag or tripod next time at the range…Some of the rifles I shoot actually shoot worse if you restrict the natural movement under recoil. Especially if you are shooting a synthetic stock that isn't the greatest to begin with.
MemberMarch 6, 2015 at 5:05 am1 Bullseye
Great, thanks for sharing all of your knowledge dog down. i was getting slightly discouraged! I also have a t3 in .243 that the wife uses and that thing factory with good loads is easy 5 group shots in a quarter @ 100yds. thats off the sled and cold bore first shot and a pause between. I couldnt let the wife out shoot me! all joking aside i really appreciate your help. i will give your suggestions a try and see what i come up with.
MemberMarch 25, 2015 at 2:22 pm1 Bullseye
Did you find a solution to your problem? With my TAC 308 I was getting a much smaller version of what you are describing. With the recoil lug, improved more relaxed shooting technique and about 300 rounds through the barrel I'm managing 1/4″ 3 shot groups and without my error 5 shot groups with AMAX factory ammo. Being different barrels I don't know if it helps but mine likes about 40-50 rounds through after a full cleaning before it gets real consistent.
MemberJuly 10, 2015 at 2:58 pm1 Bullseye
If this is a cold bore issue as hypothesized, how about shooting a couple cheap rounds first to warm up the barrel, then switching to your handloads/match ammo for practice?
MemberJuly 10, 2015 at 10:42 pm105 Bullseyes
It's a lite barrel so you only have 3 consecutive shots before it over heats…warming up the gun does nothing to help group size. Its not a heavy barrel target gun.
You need to fire 3 shots as close to the same barrel temp as possible or your group will open up.
Meaning 3 completely cold bore shots, total cool down between shots or fire them as fast as you can before you heat soak the barrel.
MemberJuly 20, 2015 at 4:32 pm1 Bullseye
I have the same issue with my .300 Win Mag, so I am putting a new, heavier barrel on it, together with a Remington style lug. The torque settting for the factory plastic stock is 35 inch pounds. Any more than that can permanently splay the stock and will further damage grouping potential. If that happens you will need to bed the stock.
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