Sierra 88 TMK Load Data

[mtnbound]

What speed didn’t it get with the 88 & n555? Barrel length and twist

18"- 7.5 twist, 2940av, 40.5gr, CCI200.

 

[NWBLKTAIL]

Update on load dev for 223 Rem, H4895, 450 primers, Lapua brass:

Shot 5 new charges tonight. Got to 2,723 fps with 23.9 grains, ended at 2,769 with 24.3 grains. All same POI and no pressure signs. Seating .035" off (2.51"OAL). I have 2 of the older gen MDT poly mags that fit up to 2.55" OAL.

Pleased at 2,700 fps+ w/excellent accuracy. Seems I'll get to 2,800 fps with 24.5 grains. Might start to sense a little powder crunch at 24.5 so no interest to go faster.

I didn’t use H4895 for 88’s today, but I did with 73 eldm and 75Eldm first time using it.

24gr seemed right on the edge to me with both those bullets. 23.5 seemed more reasonable.

I know components can make the difference, this was all with 1x fired 5.56 Starline.

Ive never used H4895 before today, I’ll be interested to see how your brass holds up. I may load some tonight at 23gr to see if it’s worth pursuing with 88’s

Edit: I see now you have about .100 extra freebore over standard 223. Read right over that initially

 

[mt terry d]

223 AI tikka 1:8 twist

Trued at 800 yards. Figures out at 2725 fps Seemed stable to me.

And Quick Drop lines up to within 0.1 mil out to 700 yards

 

[Hill Difficulty]

NWB

Seems my chamber cut aligns for maxing out a 223 Rem's use for the 88 TMK, OAL/inner mag length, and case volume.

For 223 Rem I've used Varget and H4895 almost interchangeably. My pet load for 75 ELDm is 24.5 grains of Varget @ 2,765 fps. Can use my 22CM if more speed matters. Anyway, when gathering load info for the 88 TMK I poured 24 grains of Varget into a case to get an idea on powder fill. Varget was too much fill for the bullet to fit at max seating, so worked with H4895.

To settle my 88 TMK curiosity am gonna find out what fps I get at 24.5 of H4895, then probably settle at 24.0 cuz it exceeds my speed expectations.

 

[NWBLKTAIL]

I ran out before the weather turned again today. It was really breezy almost didnt shoot at distance but had to know.

Swapped scopes last night got a rough zero, shot a “group” and tried a few other things at 100 yards got some data from the Garmin and sent them.


1/2” dots
H4895 may be the secret sauce for my barrel, but varget is not ‘bad’.

Shot what I had remaining at. 506 yards at 10” steel in 10-15mph winds coming from 7-8 o’clock. Gust higher.

I would not have tried at all but I’ve shot this spot enough i was confident as long as I have a good load and data.

Hardest part was it was variable so I did miss but only due to wind.






I whiffed 4 times but the rest connected. There is a scope adjustment in there too, bringing impacts higher. You can see the first 4 hits low.

This was off my pack with a Monilator and LS wild rear bag.

 

[Thegman]

I ran out before the weather turned again today. It was really breezy almost didnt shoot at distance but had to know.

Swapped scopes last night got a rough zero, shot a “group” and tried a few other things at 100 yards got some data from the Garmin and sent them.

View attachment 1052707
1/2” dots
H4895 may be the secret sauce for my barrel, but varget is not ‘bad’.

Shot what I had remaining at. 506 yards at 10” steel in 10-15mph winds coming from 7-8 o’clock. Gust higher.

I would not have tried at all but I’ve shot this spot enough i was confident as long as I have a good load and data.

Hardest part was it was variable so I did miss but only due to wind.




View attachment 1052714

I whiffed 4 times but the rest connected. There is a scope adjustment in there too, bringing impacts higher. You can see the first 4 hits low.

This was off my pack with a Monilator and LS wild rear bag.

It's interesting that I don't think we've even seen a 1 in 8 that hasn't shot the 88TMK well since starting this thread. Apparently my Tikka 1 in 8 Superlite wasn't just a weird fluke after all.

 

[NWBLKTAIL]

It's interesting that I don't think we've even seen a 1 in 8 that hasn't shot the 88TMK well since starting this thread. Apparently my Tikka 1 in 8 Superlite wasn't just a weird fluke after all.

I was quite surprised, going to load the rest of what I have with H4895 and see how that does.

 

[Thegman]

More 88TMK + 1 in 8 Tikka success...

I was just messing with some different powders and 80 ELD-M in my Tikka Superlite and decided to shoot @B_Reynolds_AK s patented 88TMK super-load.

L to R is:
80 ELD-M + Varget - Just under 1" for 3
80 ELD-M + RL15 ~ 3/4" for 3
80 ELD-M + TAC ~ 3/4" for 3
And... 88TMK + LVR ~ 1/2" for 3 and ~2,755

(Yeah, I know, 3 shot groups - look at their similar impacts for 4 powders, 2 bullets and total composite group size - any one of them would be adequate, but the 88TMK looks at least as good as any of the others.



88TMK load

 

[Nine Banger]

14.5" PVA 22 Creed
88TMK 2.680"
37gr= 2658fps
38gr= 2718 fps
38.5gr= 2746

I'm not seeking pressure but one was poppy on the 38.5 load. My goal was to find where I can load for best hit rates at 0DA, 3000DA and 5000DA and line up with Quick Drop.

I'm going to try H4831SC when it comes to fill the case up but H4350 works pretty good even tho its a salt shaker for case capacity.

 

[rbutcher1234]

I am switching gears from 22CM and just focusing on my 6BR. Would anyone here want any of my 88 TMKs? I have 800 unopened.

 

[Nine Banger]

I am switching gears from 22CM and just focusing on my 6BR. Would anyone here want any of my 88 TMKs? I have 800 unopened.

Tempting but I think I have enough to burn both my barrels and I believe I will abandon the cartridge as well.

 

[Nine Banger]

I'm going to try H4831SC when it comes to fill the case up but H4350 works pretty good even tho its a salt shaker for case capacity.

22 Creedmoor
14.5" BBL
2.680"
42.5gr H4831SC
2750fps

This is at pressure. 43gr was over.

The case is still not full. The answer for that must be somewhere in here:

 

[Nine Banger]

22 Creedmoor
14.5" BBL
2.680"
42.5gr H4831SC
2750fps

Windy last night:


Still this AM, 2 5 round strings:


.1mil L Turret Slip:



I'm going to ride this load for the rest of the barrel.

 

[NWBLKTAIL]

Got out again today, These were the first 10 rounds out of the gun.

T3x OEM barrel 8TW 22” approaching 1300 rounds on the barrel.

88 TMK
23gr H4895
CBTO: 1.930
2x fired Starline 5.56
CCI 450’s

Avg. 2725fps per Garmin

Took a video of shooting out to 506yds today, but cannot upload it. Had a string where wind held steady and I sent (2) 4 rounds mags as fast as I reasonably could. All eight connected. Mirage was viscous shooting midday and variable winds.

One of these days I’ll get a good recording early in the am with no wind or mirage. But super pleased with these bullets so far. Very consistent even though on paper it says they should not be.

Have 500 more coming, and acquired 3lbs more of H4895

 

[bigunit]

Group on the left is 40gr n555. Group on the right is 39.5gr n555 in non fire-formed 22-250 rem brass. Getting 3114 and 3175 fps respectively. This is with a 22-250 ackley improved 20" barrel. Ordered 5 more boxes of bullets. That should take me to the end of this barrel.

 

[SloppyJ]

22 Creedmoor
14.5" BBL
2.680"
42.5gr H4831SC
2750fps

This is at pressure. 43gr was over.

The case is still not full. The answer for that must be somewhere in here:

View attachment 1053668

Have you tried N560? I think that's where I'm going to start. Got two 18" 22cm PBB barrels that measure the exact same for CBTO on the 88s. If one shoots better, I'll give it to my son since he won't burn it down like I will. I have some 80.5s that @Gstew1930 recommended and I'm wanting to try those too.

 

[Gstew1930]

Have you tried N560? I think that's where I'm going to start. Got two 18" 22cm PBB barrels that measure the exact same for CBTO on the 88s. If one shoots better, I'll give it to my son since he won't burn it down like I will. I have some 80.5s that @Gstew1930 recommended and I'm wanting to try those too.

 

[Nine Banger]

Have you tried N560?

I don't have any.

Here's what I had on hand that I tried with the 88's in my 18" barrel:

88 TMK! 3/13/26

18” PBB barrel 1:7.5” twist 2.685” OAL (2775 fps)

44gr H1000 is 2775 fps

45.5gr Staball HD is 2775fps (46.3gr Staball HD is 2850fps…full…like stuffed)

39 gr H4350 is 3025FPS, too hot, go 38.5 next time

40.8gr Staball 6.5 is 3050 fps

Verify 44gr N565 is 2900fps. Is 42.5gr 2775fps? (STUFFED)

 

[Gstew1930]

I don't have any.

Here's what I had on hand that I tried with the 88's in my 18" barrel:

88 TMK! 3/13/26

18” PBB barrel 1:7.5” twist 2.685” OAL (2775 fps)

44gr H1000 is 2775 fps

45.5gr Staball HD is 2775fps (46.3gr Staball HD is 2850fps…full…like stuffed)

39 gr H4350 is 3025FPS, too hot, go 38.5 next time

40.8gr Staball 6.5 is 3050 fps

Verify 44gr N565 is 2900fps. Is 42.5gr 2775fps? (STUFFED)

What brass are you using?

 

[Nine Banger]

What brass are you using?

Hornady 6.5 CM Match turned into 22 Creed. I put One Shot on the case body and powder graphite on the neck and crank em out and then trim. I trim them again after fire forming and that's it.

I should reorganize that list above for public posting:


Near Pressure Loads:

39 gr H4350 is 3025FPS, too hot, go 38.5gr

40.8gr Staball 6.5 is 3050 fps

H4381SC max loads are going to be around 42.5gr (2750 fps in 14.5" barrel)


Quick Drop Loads: (you can't get pressure with these powders)

44gr H1000 is 2775 fps

45.5gr Staball HD is 2775fps (46.3gr Staball HD is 2850fps…full…like stuffed)

Verify 44gr N565 is 2900fps. Is 42.5gr 2775fps? (44gr is STUFFED)


I cut one 18" barrel down to 14.5" given my speed goals and I'm sending the other one to get cut so it will be ready to go when the barrel I'm shooting is worn out. H4831SC is my jam right now. Delightful accuracy.