88 TMK Loading Thread

[Jmedin]

Tikka T3X 1:8 twist 223 AI 88 TMK 18" bbl suppressed
3800 ft elev. 50 degrees

According to my MagnetoSpeed Chrono, 88 ELDMs are @ 2800 fps MV with
same case/powder/primer combo. 0.015 jump
I haven't trued this yet but I'm pretty optimistic
it will replace the 77 TMK as my top hunting bullet of choice ( which I've been
extremely happy with.)
Will do some ten shot groups to get a real zero.

First ten bullets out of the gun.
Adjusted scope after first group
X grains in top and X+0.5 grains in lower
1" dot

What’s your load?

 

[mt terry d]

Lake City brass, CCI 450, LeverEvolution

 

[SeanM243]

Two more small hogs down to the 88 TMK, both DRT. Impact velocity on both these would be around 2600 fps. I was unfortunately in a crunch so I didn't clean either one.

 

[Thegman]

Two more small hogs down to the 88 TMK, both DRT. Impact velocity on both these would be around 2600 fps. I was unfortunately in a crunch so I didn't clean either one. View attachment 1050047

Did you get exits on both shots? If so, what size do they tend to be?

 

[B_Reynolds_AK]

So my load of 25.0 of N150 with the 88’s that was working fine, is now popping primers. Backed off to 24.5 and the last 6 rounds I fired this evening popped out as well.

FWIW, I’ve never popped a primer in my 223, even when working up higher than that to find pressure, until I messed with the NAS3 cases and had those primers all either puncture or come out last week. Related? There is a slight ridge a few mm down from the tip of my firing pin from firing those NAS cases.

1x fired ADI brass. I have Starline 5.56 brass on back order and also Lever powder on hand to try.

 

[Thegman]

So my load of 25.0 of N150 with the 88’s that was working fine, is now popping primers. Backed off to 24.5 and the last 6 rounds I fired this evening popped out as well.

FWIW, I’ve never popped a primer in my 223, even when working up higher than that to find pressure, until I messed with the NAS3 cases and had those primers all either puncture or come out last week. Related? There is a slight ridge a few mm down from the tip of my firing pin from firing those NAS cases.

1x fired ADI brass. I have Starline 5.56 brass on back order and also Lever powder on hand to try.

Are you using the same firing pin as the one exposed to popped primers with the NAS3 cases? Check to see if/how much deformation on its tip. Sounds like there's some.

I know with ARs, firing pins can be ruined by popped primers pretty easily, but really easy to replace in that case.

Another spot to check is the firing pin hole in your bolt face. Look to see if that has been catered/eroded by gasses. Another thing that happens with ARs at times.

 

[SeanM243]

Did you get exits on both shots? If so, what size do they tend to be?

Yes, both exited on those. The one on the left, the exit side is pictured. The one on the right, entrance side is pictured, exit size was about dime size with no bones hit as my shot was a little back.

 

[Castle Rock]

So my load of 25.0 of N150 with the 88’s that was working fine, is now popping primers. Backed off to 24.5 and the last 6 rounds I fired this evening popped out as well.

FWIW, I’ve never popped a primer in my 223, even when working up higher than that to find pressure, until I messed with the NAS3 cases and had those primers all either puncture or come out last week. Related? There is a slight ridge a few mm down from the tip of my firing pin from firing those NAS cases.

1x fired ADI brass. I have Starline 5.56 brass on back order and also Lever powder on hand to try.

Probably time to get it borescoped, my money is on a problem in the neck area, either a carbon buildup or long cases pinching the neck.
If that’s not it maybe your die adjustment is out and cases are being sized too short.
I don’t think it’s the firing pin.

 

[FB Trout]

For craps and giggles I loaded up a bunch of these 88s in both Nas3 and unfired Starline .223 cases, and shot them both out of a factory Tikka .223 18” barrel 1/8 twist and a 16” factory .223 barrel 1/8 twist. The 18” tube has 2-3k rounds down it and I hit lands at 2.49” COAL and the 16” tube has 2-3 hundred rounds down it, hitting lands at 2.45” COAL. I loaded the rounds to 2.43” COAL in both cases with my standard 77 TMK load, 23.6 XBR 8208, CCi 450 primers. Yes, that’s spicy for the Starline brass with this bullet, but other than slight primer cratering, which I see periodically on my 77 TMK load, I had no stiff bolt, ejector swipes, etc., brass appeared the same as the 77 TMK load. I’m giving up on the NAs3 cases, though, at least with this bullet, as seating is very difficult and leaves a big ring and deforms the bullet at the tip, which is not present with the Starline cases. I tried lubing the necks in with Oneshot, and that minimally helped. I’ve had the same issue with certain lots of 77 TMK in the Nas3 cases, some lots seat well, some deform as per above. Ascension Industries mags were used as well….

18” Nas3-2625 FPS average
18” Starline-2690 FPS average
16” Nas3-2535 FPS average
16” Starline-2620 FPS average

I didn’t shoot at 100 yards, didn’t adjust my zero set for 100 yards either 77 TMK, didn’t shoot for groups, just dialed 1.2 MILs both rifles, and sent it at the 300 yard 8” plate. They all hit as per expected, meaning they appeared to be stable at my DA, which today is 6620. Food for thought, and I haven’t shot at longer distances yet to see if BC holds up, but interesting, nonetheless.

 

[B_Reynolds_AK]

I changed up some components today.
I went from the N150 & Fed 205’s to
Lever and CCI 450’s.

When I compared side by side, N150 had more of a crater to the primer than Lever, both with 450’s.

Loaded 10 rounds of the 88 TMK’s with 25.0 of Lever.
The result is shown below, which is probably the smallest group I’ve ever shot with this Tikka, including with the ADI 55 Blitzkings. 2650 fps avg for the ten rounds.

However I also have had to work on my firing pin a couple times now with a file and sand paper to try and correct the damage from firing the NAS rounds. The last bit of work was directly on the end of the pin, flattening it down a little as it didn’t look quite right. This led to 2 misfires during this group. I just went ahead and ordered a new T3x firing pin from Midwest Gun Works.


10 rds of 88 TMK’s.
.38” group.

 

[mtnbound]

I changed up some components today.
I went from the N150 & Fed 205’s to
Lever and CCI 450’s.

When I compared side by side, N150 had more of a crater to the primer than Lever, both with 450’s.

Loaded 10 rounds with 25.0 of Lever.
The result is shown below, which is probably the smallest group I’ve ever shot with this Tikka, including with the ADI 55 Blitzkings. 2650 fps avg for the ten rounds.

However I also have had to work on my firing on a couple times now with a file and sand paper to try and correct the damage from firing the NAS rounds. The last bit of work was directly on the end of the pin, flattening it down a little as it didn’t look quite right. This led to 2 misfires during this group. I just went ahead and ordered a new T3x firing pin from Midwest Gun Works.
View attachment 1050404

I’d say keep that firing pin as a backup and order a new one. That many blown primers takes its toll.

Assuming this Lever load was with 88’s?

I guess I’ll have to see if I can find some Lever.

 

[B_Reynolds_AK]

I’d say keep that firing pin as a backup and order a new one. That many blown primers takes its toll.

Assuming this Lever load was with 88’s?

I guess I’ll have to see if I can find some Lever.

Correct, 88’s. I probably have pierced or blown 30 primers since starting with the NAS cases and now into brass cases as well.

Smoothing out the pin around the diameter of it has definitely led to more of a gap around the firing pin hole on the bolt face too.

 

[KyleR1985]

I changed up some components today.
I went from the N150 & Fed 205’s to
Lever and CCI 450’s.

When I compared side by side, N150 had more of a crater to the primer than Lever, both with 450’s.

Loaded 10 rounds of the 88 TMK’s with 25.0 of Lever.
The result is shown below, which is probably the smallest group I’ve ever shot with this Tikka, including with the ADI 55 Blitzkings. 2650 fps avg for the ten rounds.

However I also have had to work on my firing on a couple times now with a file and sand paper to try and correct the damage from firing the NAS rounds. The last bit of work was directly on the end of the pin, flattening it down a little as it didn’t look quite right. This led to 2 misfires during this group. I just went ahead and ordered a new T3x firing pin from Midwest Gun Works.


10 rds of 88 TMK’s
View attachment 1050404

Welcome to the dark side. Lever is a helluva drug.

What overall length?

 

[Hill Difficulty]

Recently bought some 88 TMKs. Initial takeaways were long bearing surface and gonna take up a lot of case volume, even with a long-throated chamber. After seeing all the lower 22CM speeds reported thought I'd end up in the 2,500s.

• Loaded 7 starter charges of H4895 up to 23.5 grains. Shot them up tonight.
• 223 Rem with 17" barrel w/ 1:7" twist. BTO @ 1.99", seated at 2.50" COAL.
• Lapua brass, CCI 450 primers.
• Velocity at 2,667 fps with 23.5 grains and no signs of pressure.
• All 7 charges had the same POI so accuracy won't be an issue.

Next will be to load up 5 or so charges to see if I can get to 2,700 fps. Have the older 2.55" MDT mags so can seat the bullets out a bit further to stay in front of powder crunch.

Headed to TX in a few weeks to hunt a bit so will bring this rig and give the 88s a go. Will report in a few days after shooting through the increased loads.




EDIT to add that I'm confident I'll get a tad over 2,700 fps without compressing H4895. Note that I started with Varget and noticed immediately that powder was filling too high in relation to bullet base.

 

[NWBLKTAIL]

So my load of 25.0 of N150 with the 88’s that was working fine, is now popping primers. Backed off to 24.5 and the last 6 rounds I fired this evening popped out as well.

FWIW, I’ve never popped a primer in my 223, even when working up higher than that to find pressure, until I messed with the NAS3 cases and had those primers all either puncture or come out last week. Related? There is a slight ridge a few mm down from the tip of my firing pin from firing those NAS cases.

1x fired ADI brass. I have Starline 5.56 brass on back order and also Lever powder on hand to try.

Fwiw

I’ve been using that Starline 5.56 brass, 200 pieces have 4 firings, haven’t reached book max case length. All the primer pockets are still tight. No weirdness so far very happy. Have 300 more virgin still bagged and 100 1x fired. All my loads have been with CCI450’s.

 

[NWBLKTAIL]

I can’t take it, I’m gonna have to order a 7tw barrel.

 

[B_Reynolds_AK]

Welcome to the dark side. Lever is a helluva drug.

What overall length?

.100 fb
CBTO: 1.940
OAL: 2.50

 

[B_Reynolds_AK]

Fwiw

I’ve been using that Starline 5.56 brass, 200 pieces have 4 firings, haven’t reached book max case length. All the primer pockets are still tight. No weirdness so far very happy. Have 300 more virgin still bagged and 100 1x fired. All my loads have been with CCI450’s.

Nice, thank you. Care to share your powder and charge weight as well?

I ordered the same brass, but it’s on unknown back order. Local shop had Lapua in stock, so I bought a 100 to try out, but won’t do that until I get the new firing pin.

 

[NWBLKTAIL]

Nice, thank you. Care to share your powder and charge weight as well?

I ordered the same brass, but it’s on unknown back order. Local shop had Lapua in stock, so I bought a 100 to try out, but won’t do that until I get the new firing pin.

I could for sure but not sure how relevant it would be to you. I have an 8twist OEM so no 88TMK experience.

 

[longrangelead]

I just received 2-3rd and 2-4rd 223XL (2.70") mags from @pods8 (Rugged Stitching)

i cycled 2.25" 223 through them several times and they feed perfect.
then I cycled 2.55" 6x45 through them, they also cycled perfect.
Then at the range, cycled/fired what I had loaded. zero issues.

These may be exactly what the 223/6x45 w/heavies needs to maximize their potential.

6x45 w/107 TMK 2.55"
next to ADI 556 55gr tgk