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Posted: 2/16/2018 7:03:25 AM EDT
[#1]
I settled on 23.2 grains, seated to max mag length. Can’t help with velocity, but they shoot under 1” at 100 yards, and I’ve gotten some .75” groups.
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Posted: 2/16/2018 7:05:53 AM EDT
[#2]
Quote HistoryQuoted:
I settled on 23.2 grains, seated to max mag length. Can’t help with velocity, but they shoot under 1” at 100 yards, and I’ve gotten some .75” groups. 23.2 is what ive been using for the 77gr otms and most groups are right at 1" with about 25% sometimes doing .5 |
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Posted: 2/16/2018 7:22:57 AM EDT
[#3]
I'd back off the SMK load by 1.0gr and work up in 0.3gr increments. The bullet OAL is about 0.015" longer, but the bearing surface is shorter and the jump is longer.
You're pretty much stuck at 2.26". However, LRRPF52 has seen 75gr AMAX work at maglength, so maybe the TMKs could perform similarly with the ogive below the mouth if seated below 2.26". |
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Posted: 2/16/2018 8:27:27 AM EDT
[#4]
 Attached FileNo ogive in case neck. Also no pressure signs on fired brass. Obviously start a few grains lower and work up as with any (especially internet) load. Brass is WCC of various dates. Gun used. 18” 8 twist barrel btw.  Attached File |
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Posted: 2/16/2018 10:46:20 AM EDT
[#5]
Can't speak directly to the 77's but when I picked up some 69's to play around with I had the same issue with lack of established data. I called Sierra and they told me to use SMK data.
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Posted: 2/16/2018 12:05:24 PM EDT
[#6]
Quoted:
usually load the sierra 77gr OTMs but recently got 1000 of the 77gr TMK in a trade. Cant seem to find any data on it through google or any of my books. Anyone have any info on what i should be doing with these? Wanted to load them over 8208xbr since i have a lot of it. Thanks. 24.1gr of 8208 XBR, LC case, CCI 400 primer, seated to mag length, yields half inch groups for me. I dont shoot many of them though, only 200 so far, because my gun shoots Hornady BTHPs just as well for alot less money. |
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Posted: 2/16/2018 7:05:01 PM EDT
[#7]
Quote HistoryQuoted: Use the same data you use for your OTMs. As others has said, Sierra recommends using the 77gr SMK data. 24.1gr of 8208 XBR, LC case, CCI 400 primer, seated to mag length, yields half inch groups for me. I dont shoot many of them though, only 200 so far, because my gun shoots Hornady BTHPs just as well for alot less money. |
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Posted: 2/16/2018 10:20:34 PM EDT
[#8]
Quote HistoryQuoted:
I bet that is smoking. I am loading the 77tmk with 23.2 gr 8208xbr at magazine length and getting 2700 fps in an 18" barrel. You're almost a full grain heavier...are you using a long drop tube? HP shooters step over max often, but I don't recall any over 23.5gr 8208. |
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Posted: 2/16/2018 10:35:46 PM EDT
[#9]
Quote HistoryQuoted: Use the same data you use for your OTMs. As others has said, Sierra recommends using the 77gr SMK data. 24.1gr of 8208 XBR, LC case, CCI 400 primer, seated to mag length, yields half inch groups for me. I dont shoot many of them though, only 200 so far, because my gun shoots Hornady BTHPs just as well for alot less money. I thought I was pushing it with 23.5 gr. |
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Posted: 2/16/2018 11:51:24 PM EDT
[#10]
I run XBR with the TMK, my accuracy loads are at 22.6 and 23.2 gr.
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Posted: 2/17/2018 11:30:48 AM EDT
[#11]
Quote HistoryQuoted:
I run XBR with the TMK, my accuracy loads are at 22.6 and 23.2 gr. |
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Posted: 2/17/2018 11:54:36 AM EDT
[#12]
Quote HistoryQuoted:
There's always the implied warning, but I'd put a warning on his load. HP shooters step over max often, but I don't recall any over 23.5gr 8208. |
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Posted: 2/17/2018 3:51:05 PM EDT
[#13]
Quote HistoryQuoted: Use the same data you use for your OTMs. As others has said, Sierra recommends using the 77gr SMK data. 24.1gr of 8208 XBR, LC case, CCI 400 primer, seated to mag length, yields half inch groups for me. I dont shoot many of them though, only 200 so far, because my gun shoots Hornady BTHPs just as well for alot less money. |
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Posted: 2/17/2018 4:48:36 PM EDT
[#14]
23.2 gr loaded a hair short of max
Getting a little less than 1 moa. Shoots the same for me as 77 SMK but only took it out a few hundred yards. |
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Posted: 2/17/2018 7:17:13 PM EDT
[#15]
I just started working with these myself. With XBR 8208, unsorted LC NATO brass, and Remington 7 1/2 primers, I hit a node at 22.3 grains, and it appeared I was nearing one at 23.0, but I started getting pressure signs. The extra grain only buys me about 80 fps on the average. Stdev numbers for 22.3 landed around 9 fps IIRC, out of my 18" SPR.
Just received 600 more of the TMKs that I'll be loading up over the next week 
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Posted: 2/17/2018 8:55:34 PM EDT
[#16]
Great bullet, excellent choice of powder, work up to the max/accuracy load in your rifle and enjoy.
They have shot well in everything I have tried them in seated from 2.26" to 2.31"+ in mags that allowed longer or to 2.32" in bolt actions. Very accurate. |
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Posted: 2/19/2018 1:38:21 PM EDT
[#17]
Quote HistoryQuoted: loading to 2.26" ? lots of people here saying to load to max length and other places people are saying 2.5 to 2.55 |
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Posted: 2/19/2018 4:36:48 PM EDT
[#18]
Quote HistoryQuoted:
loading to 2.26" ? lots of people here saying to load to max length and other places people are saying 2.5 to 2.55 My average is 2.255". Regular SMKs vary more, so 2.250. VMAXs vary less so maybe 2.257" |
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Posted: 2/19/2018 5:48:48 PM EDT
[#19]
Quoted: I seat mine to 2.245" Quoted:
2.26" max minus average nose length variation and some for neck tension or press slop variation. Most tipped bullets have 3-4 thou variation. My average is 2.255". Regular SMKs vary more, so 2.250. VMAXs vary less so maybe 2.257" |
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Posted: 2/20/2018 1:54:43 PM EDT
[#20]
Quote HistoryQuoted:
I bet that is smoking. I am loading the 77tmk with 23.2 gr 8208xbr at magazine length and getting 2700 fps in an 18" barrel. You're almost a full grain heavier...are you using a long drop tube? Quote HistoryQuoted:
Quoted: Use the same data you use for your OTMs. As others has said, Sierra recommends using the 77gr SMK data. 24.1gr of 8208 XBR, LC case, CCI 400 primer, seated to mag length, yields half inch groups for me. I dont shoot many of them though, only 200 so far, because my gun shoots Hornady BTHPs just as well for alot less money. 
My pet load falls right at 23.1gr of 8208. Which is pretty normal for what most guys are seeing +/- .2gr. Sorry about that gents. I have tested to 24gr of 8208 XBR with LC cases and tapping the case on the bench to settle the powder. Primers were flattened on the edge, but still had a clean firing pin strike with no flow (CCI 400s arent noted for their ability to be pushed hard), and light extractor marks. My rifle is a 18" rifle length gas, 5.56 chamber. 5.56 chamber does stand up to higher velocities and thus pressure better than a 223 or a Wylde chamber so that probably explains why I can always seem to eek out a little more velocity than most guys. |
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Posted: 2/20/2018 7:06:51 PM EDT
[#21]
How much more than a Wylde?
I have the approximate BTO of a 77gr SMK in a 5.56, Wylde, and whatever DPMS uses (.223 Match? Which is supposed to be .223 with a longer throat?). *Not done with Hornady OAL gauge. DPMS with ~5700rds: 1.965" DPMS ~1500rds: 1.925" Core15 ~500rds: 1.925" RRA Wylde ~500rds: 1.92" CLE ~300rds: 1.90" |
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Posted: 2/21/2018 10:56:04 AM EDT
[#22]
Quote HistoryQuoted:
How much more than a Wylde? I have the approximate BTO of a 77gr SMK in a 5.56, Wylde, and whatever DPMS uses (.223 Match?). *Not done with Hornady OAL gauge. DPMS with ~5700rds: 1.965" DPMS ~1500rds: 1.925" Core15 ~500rds: 1.925" RRA Wylde ~500rds: 1.92" CLE ~300rds: 1.90" 
Looking at this drawing, which honestly I dont even understand every bit of info on it, the L and T measurements in addition to the angle are the ones that really matter from what I can see. Figures are below. From what I can see the 223 is probably the most accurate of the 3 chambers as it does engage the bullet the fastest because of short T value with a 3 degree angle, but this could be bad as you start to get into longer 75+ gr bullets. The 5.56 chamber is very generous, with long T values with the 1 degree angle which makes sense as the 5.56 is noted for its long leade. The Wylde uses an average of the 223 and 5.56 T value, but has a slightly longer L value which stands up to how the Wylde is touted to have some of the benefits of the 5.56 but with better accuracy. Interesting bit here, every dimension before the T+L line is almost identical between a 223 and 5.56, but the Wylde actually is significantly different. 223: L = .040 T = .103 A = 3 5.56 L = .070 T = .339 A = 1 Wylde L = .078 T = .214 A = 1 If someone knows exactly what these number mean, especially the angle (ex: 3 degrees - 10) please let me know. |
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Posted: 2/21/2018 11:11:55 AM EDT
[#23]
L seems to be where the leade starts from the mouth. T is where the leade ends and bore is .218-.219 diameter from the mouth. 3*-10 is 3 degrees - 10 minutes, or 3.17 degrees.
If you look at the "supposed" message from Bill Wylde, he mentions it's based on one of the NATO prints (not THE 5.56), with the freebore diameter tightened. Everything else is nearly equal or bigger. |
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Posted: 2/21/2018 11:18:43 AM EDT
[#24]
Quote HistoryQuoted:
L seems to be where the leade starts from the mouth. T is where the leade ends and bore is .218-.219 diameter from the mouth. 3*-10 is 3 degrees - 10 minutes, or 3.17 degrees. If you look at the "supposed" message from Bill Wylde, he mentions it's based on one of the NATO prints, with the freebore diameter tightened. Everything else is nearly equal or bigger. 
I wonder what the -# means after the angle though. |
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Posted: 2/21/2018 11:24:34 AM EDT
[#25]
Quote HistoryQuoted:
I wonder what the -# means after the angle though. |
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Posted: 2/21/2018 11:25:29 AM EDT
[#26]
Quote HistoryQuoted:
Minutes of angle. 3*-10 = 3.17 degrees. |
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Posted: 2/24/2018 1:33:49 AM EDT
[#27]
got the first 25 loaded up, heading out to my range first thing in the morning to see how they do.
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Posted: 2/24/2018 2:57:53 PM EDT
[#28]
went out to go shoot, forgot my bipod and rear bag lol.
groups were 1" to 1.25" using the mag as a pod 
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Posted: 2/24/2018 4:11:02 PM EDT
[#29]
Good enough.
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Posted: 2/24/2018 10:03:50 PM EDT
[#30]
I've not loaded any tmk's yet but I'll be trying some a2520/cci 450 with them when i get a chance. As it works wonders in my 1/7wylde barrel. .490" groups with 2570 avg fps(18" barrel) with a 77smk otm. No pressure signs and never went any higher on charge as i called it good at under half an inch.
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Posted: 2/25/2018 9:43:43 AM EDT
[#31]
I just tested some TMK’s yesterday. With RL-15 I was around .78 groups. I switched to faster powders ie CFE and TAC. That’s when the wheels fell off. Groups blew out to 3” or more. Velocity was much higher than the RL-15 but accuracy was gone. Anyone else had issues pushing them faster?
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Posted: 2/25/2018 11:26:21 AM EDT
[#32]
Out of my 30" F-class Savage, 3000 fps with an over book max 23.5 gr of XBR 8208 was very accurate (2.32 OAL) has shot 200s with 10+ x counts several times at 300 yards. At 600, wind left me with more 190-194 range scores.
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Posted: 2/26/2018 2:06:19 PM EDT
[#33]
Quote HistoryQuoted:
I just tested some TMK’s yesterday. With RL-15 I was around .78 groups. I switched to faster powders ie CFE and TAC. That’s when the wheels fell off. Groups blew out to 3” or more. Velocity was much higher than the RL-15 but accuracy was gone. Anyone else had issues pushing them faster? Between those 3 powders, TAC is fastest. RL-15 is between, just a hair faster than Varget. CFE 223 is actually a hair slower than Varget. Hodgdon Burn Rate Chart |
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Posted: 2/27/2018 11:17:36 AM EDT
[#34]
Quote HistoryQuoted:
Thanks, the tmks i got from black hills are at 2.245 as well. yeah ive been trying to load my SMKs to 2.250 but the meplats are all so different that its never really 2.250 for most of them. Quote HistoryQuoted:
Quoted: I seat mine to 2.245" Quoted:
2.26" max minus average nose length variation and some for neck tension or press slop variation. Most tipped bullets have 3-4 thou variation. My average is 2.255". Regular SMKs vary more, so 2.250. VMAXs vary less so maybe 2.257" Loading for a normal mag at a COAL of ~2.255” with 23.2 grains of 8208 XBR I am seeing 2730 fps with an SD of ~8.5 for 10 shots out of an 18” KAC LPR. The 2.280” cartridges for the ASC saw a velocity drop (as expected) to around 2670, IIRC. Groups opened up slightly to around an inch, and SD increased a bit, also (13, - again IIRC). I’m planning to load more tonight and hopefully hit the range tomorrow. FWIW, the 77 TMK has proven to be an awesome coyote round. 
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Posted: 2/27/2018 11:57:42 AM EDT
[#35]
Quote HistoryQuoted: I picked up 4 of the steel ASC mags a few weeks ago and can load the 77 TMK to a COAL of 2.280”. The mags are advertised as being able to take a longer round, but in none of the four I received is that possible. Only had them out once and saw mixed results. Mags ran fine but the load needs tweaking. Loading for a normal mag at a COAL of ~2.255” with 23.2 grains of 8208 XBR I am seeing 2730 fps with an SD of ~8.5 for 10 shots out of an 18” KAC LPR. The 2.280” cartridges for the ASC saw a velocity drop (as expected) to around 2670, IIRC. Groups opened up slightly to around an inch, and SD increased a bit, also (13, - again IIRC). I’m planning to load more tonight and hopefully hit the range tomorrow. FWIW, the 77 TMK has proven to be an awesome coyote round. They shot well at the longer lengths, but it wasn't good enough to require separate mags for one load. |
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Posted: 2/27/2018 12:08:34 PM EDT
[#36]
Quote HistoryQuoted:
I also bought some of the ASC mags and played with OAL. I think I got out as far as 2.290". I never got the results I was looking for and settled on 2.255" with 23.2 XBR. They shot well at the longer lengths, but it wasn't good enough to require separate mags for one load. Quote HistoryQuoted:
Quoted: I picked up 4 of the steel ASC mags a few weeks ago and can load the 77 TMK to a COAL of 2.280”. The mags are advertised as being able to take a longer round, but in none of the four I received is that possible. Only had them out once and saw mixed results. Mags ran fine but the load needs tweaking. Loading for a normal mag at a COAL of ~2.255” with 23.2 grains of 8208 XBR I am seeing 2730 fps with an SD of ~8.5 for 10 shots out of an 18” KAC LPR. The 2.280” cartridges for the ASC saw a velocity drop (as expected) to around 2670, IIRC. Groups opened up slightly to around an inch, and SD increased a bit, also (13, - again IIRC). I’m planning to load more tonight and hopefully hit the range tomorrow. FWIW, the 77 TMK has proven to be an awesome coyote round. They shot well at the longer lengths, but it wasn't good enough to require separate mags for one load. |
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