Just got off the range they shot fine in my 8 tw f class rig.With about the same throat as the 142,s give or take.This barrel is a sweetheart so I named it after my girl friend.Now on the other hand the 8 tw sling barrel didn't like them at all,although it is a PITA so I named it after my wife!
Sierra 150 grain 6.5 Matchking
- Thread starter MLC
- Start date
swd
Silver $$ Contributor
Different brands of barrels?
Same brand the sling barrel had 80 thou runout at the muzzle along with a reverse taper in the bore .I don't expect it to shoot very well.But to be fair I have to re throat it the 142,s and 150,s seat well into the donut.
BTO measurement on the 150 SMK is .750
Just a little data on these Sierra 150's. I ran some more in my rifles today. The one rifle is chambered in 6.5X55 swede, 1 in 8 twist Brux @ 30". .175 fb on the reamer. Anyways my normal match load is 50 gr of H4831sc, Lapua brass, CCR BR2 primer and 3.060 OAL, the 142 smk is 3.075 to the lands in this rifle. The 150 SMK is 3.210 to the lands in this same rifle for comparison. But I only had to adjust probably .020 on my micrometer seating die from the 142 to the 150 to keep both bullets roughly .015" off the lands
50 gr H4831sc, 142 smk = 3065 fps
49 gr H4831sc, 150 smk= 2970 fps
49.5 gr h4831sc, 150 smk = 2985 fps
50 gr H4831sc, 150 smk= 3000 fps
I use a Labradar chronograph, and just checked all these within a few minutes of each other. The 49 gr load shows the most promise as the spread was within single digets. I'll try to shoot some 1000 yd groups later on, well it's 980 yards to be exact to that target.
My 260 wears a Brux 1 in 8 twist barrel @ 26" but has a short throat to seat 140 class bullets at mag length. I son't think the 150 will be a good match in this rifle and velocity will be low.
50 gr H4831sc, 142 smk = 3065 fps
49 gr H4831sc, 150 smk= 2970 fps
49.5 gr h4831sc, 150 smk = 2985 fps
50 gr H4831sc, 150 smk= 3000 fps
I use a Labradar chronograph, and just checked all these within a few minutes of each other. The 49 gr load shows the most promise as the spread was within single digets. I'll try to shoot some 1000 yd groups later on, well it's 980 yards to be exact to that target.
My 260 wears a Brux 1 in 8 twist barrel @ 26" but has a short throat to seat 140 class bullets at mag length. I son't think the 150 will be a good match in this rifle and velocity will be low.
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Distance to jam in my rifle:
147g ELD-M. 2.623
150g SMK. 2.632
155g Cauterucio. 2.631
Hope that helps someone.
147g ELD-M. 2.623
150g SMK. 2.632
155g Cauterucio. 2.631
Hope that helps someone.
I have been loading the 142 SMK in the 260 Remington for shooting 1000 yards and that bullet has been doing well in that application even though it sticks into the case well past the neck. I started today to load some 260 Remington ammo to test to see how the new 150 SMK bullet compares to the 142 SMK in this application. I have been concerned about the 6.5mm 150 SMK bullets sticking into the case more than the 142 SMK which already is not favorable in this regard. However after making measurements, when loaded to touch the lands the overall cartridge length with the 150 SMK more than makes up for the additional bullet length and sticks into the case slightly less than the 142 SMK. The 150 SMK may not do well in the 260 Remington but it looks like this is one factor that is not a problem.
Hi mate is that using a comparator for 6.5 bullets? Reason I ask as I have done a lot of searching on BTO measurements for various 6.5 bullets on the net and the numbers vary wildly based on what comparators people use. With my hornady 6.5 comparator I get .682 for 123 scenars and .717 for 139 scenars. If your comparator is the same they are not all that much longer than 139 scenars.
wboggs
Gold $$ Contributor
Mine seat to within 0.02" of the 142 smk. Almost all the additional length is in the nose forward of the ogive and they are much longer overall.
Stability in the 1-8 twist will be the question.
I'm in the process of some loading to determine this since I doubt there are many 1-7.5s out there. Should be interesting.
Stability in the 1-8 twist will be the question.
I'm in the process of some loading to determine this since I doubt there are many 1-7.5s out there. Should be interesting.
The comparator used in a Sinclair model with inserts that clamp to the caliper jaws. I zero out the caliper before measuring so that the reading is correct. With that said, all comparator devices will vary from product to product.
I hope this helps,
Lloyd
Hello Lloyd.. In your previous post you mentioned a .775 BTO on the 150SMK.. In my earlier 6.5 x 284s and now in my .260A.I.s I always used a .170freebore. That handled all 139-140 class bullets. That reading of .775 would put the freebore of my new 6.5 x 284 at a MINIMUM of .185 and .200 MIGHT be better! What are your thoughts, as I still need to order a reamer??
What brand were they? Kinda surprised to hear whoever's it is would let a reverse taper bore slip out. Musta been awful lapping job..?
Actually the bore looked good.And the fine folks are sending another barrel,kudos to our group of people.
Hello Ben,
I posted a .750 BTO measurement but I'm not currently running a 6.5mm. (That is about to change) My shooting partner supplied me with the measurements, an average over 10 bullets. If your chamber FB is to short, you could always go in with a throating reamer and remove the material necessary to get the stars to line up.
I'm sorry I can be of more help with a free bore length.
Lloyd
wboggs
Gold $$ Contributor
Tried a couple loads in my standard .260.
Best accuracy with a H4350 load at 2799fps. This was the highest load I tested and could be increased to about 2850 since I had no case head expansion.
R17 gave about 75-100 additional velocity with no case head expansion but accuracy was poor. Could get 2875-2900 if I could find an accurate load. All loads in a 30" Krieger with 0.165 throat and 0.065 lead in.
Wish I could get the R17 to shoot.
Anyone have any suggestions?
Thanks
Bill
Best accuracy with a H4350 load at 2799fps. This was the highest load I tested and could be increased to about 2850 since I had no case head expansion.
R17 gave about 75-100 additional velocity with no case head expansion but accuracy was poor. Could get 2875-2900 if I could find an accurate load. All loads in a 30" Krieger with 0.165 throat and 0.065 lead in.
Wish I could get the R17 to shoot.
Anyone have any suggestions?
Thanks
Bill
RL-16 gives very good results with 140's in a 6.5 Creedmoor (I get better results than H4350). I use RL-23, 49.4gr under a 142gr in 6.5 x55 BJAI (case cap of 62-63 gr H20) with excellent grouping at 600yds. I would think it could be fast enough for the smaller case of the .260 with a heavy 150gr.
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