Sierra 88 TMK Load Data

[KyleR1985]

I have some loaded but haven’t shot yet.

My LC brass is 32.5+gr h2o.

77’s shot great at 24gr loaded 2.375” (.125” off lands).

You’ll be fine starting at 22gr if you’re over 2.4”

 

[cq0302]

This thread is enough motivation to spin on my 22-250 barrel, order some brass tonight

Encouraging seeing everyone’s results

Lapua or bust, they’re hard on brass as is, with heavies I tend to end up higher on pressure and cheaper brass doesn’t last

 

[NWBLKTAIL]

Lapua or bust, they’re hard on brass as is, with heavies I tend to end up higher on pressure and cheaper brass doesn’t last

I’ve since sold both of those 22-250 barrels I had, but lapua was what I Initially bought.

I got them flying well out to 500 yards so far, uploaded a video in post #354 that’s with my standard 8twist tikka 223

 

[cq0302]

Have you tried N560?

Not 22cm, but my 22-250 loves n560 with 88s and 85.5s, 38.5gr

 

[cq0302]

I’ve since sold both of those 22-250 barrels I had, but lapua was what I Initially bought.

I got them flying well out to 500 yards so far, uploaded a video in post #354 that’s with my standard 8twist tikka 223

Hard to complain about those results.

 

[SloppyJ]

Not 22cm, but my 22-250 loves n560 with 88s and 85.5s, 38.5gr

Got some N555 and N560 loaded up to test for my new 22cm with 88tmks. Have high hopes for the 560.

 

[cq0302]

Got some N555 and N560 loaded up to test for my new 22cm with 88tmks. Have high hopes for the 560.

I’ve had excellent results with 560 in several rifles, I think it is overlooked on many of the slightly overbore options, 22-250, 6cm, even 6.5cm with heavy bullets

 

[rafiki]

any help/advice on diagnosing my issue or what you’d try next?

tikka 22cm
PBB 16.25” 1-7.5tw .120 FB (brand new)
rs1.2
scythe ti airlock nano
DA 3,150 ft

first 6 rnds thru the barrel were factory 80 ELDX to zero scope avg 2,932 fps

load 1
-88 tmk
-43.5 gr stball hd
-peterson lrp (unfired)
-cci 200
-2.7 coal
-2,600fps

load 2
-88 tmk
-38.5 gr h4381sc
-peterson lrp (unfired)
-cci 200
-2.7 coal
-2,524 fps

only shot a couple rnds of each hand load bc i saw light ejector swipes and heavier bolt lift. shots were spaced out 1-2 minutes. bullets were seated to 30 thou jump in my chamber based on modified case and hornady oal gauge.
lots of new variables at play so not sure if i just need the barrel to break in more or if i should be looking at one specific element on the loads/rifle system.

update to this. my issue was related to a dirty chamber and is resolved.
loaded and shot 3 rnds of 42 gr h4831sc to confirm no pressure signs.
0.195" group | avg 2775 fps velocity
barrel still only has <50 rnds on it but will stick with 4831 for now.
(bottom shot was 42.6gr so i excluded it from the group but was 2823 fps)