175 smk length

Picture hosting, Exclusive club forum, Premium recognition, and more website access are only a click away! Granted, this is a pretty stout loading for a 308 but I'm not showing any pressure signs. [ May 31, 2020 ]

See the sticky on gas gun loading for any further explanation.Again, with concern for pressure differences as a result of having to seat a longer projectile deeper in to the case, starting with a charge weight 5 to 10% lower than your standard load and working up to desired velocity while checking for pressure signs or unexpected jumps in velocity is always the safe plan.Surprisingly, working up to a 44.0 gr charge of Varget produced velocities almost exactly the same as those behind an SMK: avg muzzle velocity obtained was 2550 fps with an SD of 8.4, even despite the fact that the charges were heavily compressed (a property of Varget observed empirically for years: it’s hard to cause an overpressure load with Varget in a .308 size case).With such a small SD one would expect good accuracy. [ April 30, 2020 ] The difference downrange in a Weapons Employment Zone analysis for 20 fps of velocity is negligible. It may just be the case where it really doesn't matter that much but I've often wondered if a faster powder would work better in a shorter barrel.I haven't looked at my post lately and I'm glad to see responses this site has been great so far.Wise choice. Granted, this is a pretty stout loading for a 308 but I'm not showing any pressure signs. When you block a person, they can no longer invite you to a private message or post to your profile wall. Despite highly compressed loads, the same velocities were obtained with the same charge weights (TMK to SMK). Seated a 2nd bullet and checked ogive again, it was off by .008" and I did not readjust the seating die and resumed a 3rd and it was spot on again, 4th one was off .004" and so on. Heaver bullets are not going to come out of the rifle any faster, I'd look into the 155 Lapuas, they're BC is also slightly better than the 175 SMK. ATS Tactical Gear This is what a higher BC really does to produce value; less wind deflection, greater supersonic range.If I get motivated, I could do a ladder test to tune this load for velocity/accuracy if I really wanted to, but I think I’ll just shoot this for awhile.The TMK is superior to the SMK and I’ll switch to the TMK for use in this rifle.I have some disappointing news for gas gun shooters though.Have you noticed the TMK being more stable as it goes transonic? 20" barrel.

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I am trying out the 175 SMK again after doing a load development last week, they shot well.

You can see the difference in the start of the ogive between the two in this picture.It’s not possible to seat something to be close to the lands unless we turn our gas gun into a single load weapon. Average accuracy was .806″ (.770MOA).

We found accuracy of the TMKs mirrors what Doc found. I believe my rifle and bullets are capable, but I may need more training. The 30 Caliber 175 Grain MatchKing was developed along with military experts for use in the M21, M24 and M40A1 sniper systems. Kel-Tec RDB Survival Review: A Better Bang Stick? Cases were neck sized, trimmed to length … The secant ogive of the TMK is the most likely culprit in the poor accuracy results in the gas gun as a result of the long jump to the lands for this ogive when seated to a maximum SAAMI OAL to allow use in a magazine.The base accuracy load in this gun is a 175 SMK loaded with 44.0 gr Varget producing 2552 fps at the muzzle with an SD of 14. As a result, the TMK’s in all calibers are also about 5% to 10% longer than their SMK counterpart, and of course have different ogive lengths.This has significant impact on seating lengths and therefore on applications, as I will try and demonstrate.Result: The TMK proved to be as accurate as the SMK in this rifle, with a substantial decrease in wind deflection and drop as a result of the much higher BC and retained velocity. The groups are high left because of the different zero. Post was not sent - check your email addresses! I generally do not have luck with secant/VLD type ogives in gas guns for all the known reasons. Because this is a public effort, I'll leave this page up for others to use. Average weight was 174.7 grains with a standard deviation of .1 grain.The caliper was zeroed with both comparators in place. data is obviously wrong.

Using CCI #24 mil primers, winchester virgin cases and the 175 SMK HPBT, COL mag length.
Despite the longer design of the TMK, higher pressures/velocities were not an issue with Varget working up to the same charge weights as used in the SMK load.

Finally, you'll never receive email notifications about content they create or likes they designate for your content. While I personally did not observe this, I would suspect the longer bearing surface if accountable for this.The 175 TMK has an overall length of 1.380″, compared to 1.239″ of the SMK. I began by weighing a sample of 50 bullets on an Bullet weights ranged from 174.6 to 175.0 grains. the bullet length is the critical factor in its relationship to the calibre. Unfortunately……..With my Clip-on (CNVD) zero on the gun, I shot groups increasing in charge weights, measuring velocities with each, and looking at general group size. Copyright Lightfighter Tactical Forum 2002-2020 you don't have to enter the bullet length to calculate the drift. While this isn’t a big deal for a shooter single … All content Copyright 1998-2018 Rifleshooter.com, FTC disclosure: some links on this site are monetized

It then generated a large amount of interest by long range competitive shooters due to its high ballistic coefficient and ability to remain supersonic at 1000 yards out of a … While there are plenty of companies offering loaded I worked up some loads for my custom 22″ barrel 6.5 Creedmoor precision rifle using Sierra’s 123 Grain MatchKing (SMK) HPBT with Hodgdon Varget and H4350 powder. I will over the next couple of months integrate this data into my website so