The 6UM

For the 6um, after breaking it in and finding a good load, does it actually stay stable through the life of the barrel without having to tweak anything? Or does the quick throat erosion mean load charge tweaking every once in awhile?
 
For the 6um, after breaking it in and finding a good load, does it actually stay stable through the life of the barrel without having to tweak anything? Or does the quick throat erosion mean load charge tweaking every once in awhile?


No. Get 60-80 rounds on it, then just shoot it. It goes for 600-800 rounds without issue from the 4-5 I’ve seen, and at least that many that Ryan has had.
 
I know there is probably as many different answers to this question as there are people with 6UMs, but is there an ideal weight? I’m not a fan of carrying a tank around to help mitigate recoil, but also don’t want to build one so light that recoil thumps.

I am trying to build one on a Rokstock lite that would be around 7.5#s loaded and suppressed. Just afraid it might be too light and lead to punishing recoil (I’m quite recoil sensitive). About 6.5PRC suppressed recoil in a 9 pound rifle is about all I can tolerate.

So should I add weight to make it mo betta or keep going down this path?
 
I’m right at 8# suppressed and it’s very low recoil, less than 9.5# 6.5cm with 140 eldm factory load


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Was just about to post a question asking about the guys with less than ideal form, how does the recoil compare to a 6.5cm. Thanks for the info!
 
I’m right at 8# suppressed and it’s very low recoil, less than 9.5# 6.5cm with 140 eldm factory load


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Either I am plugging in incorrect data into a recoil calculator, you are massively downloading here, or your perception is incorrect. There is 43% more recoil with the 6UM in an equivalent weight gun compared to a 6.5CM with the attached inputs. There is no way a heavier 6.5CM is recoiling more than a lighter 6UM.

Data used is the published N570 115 DTAC load for the 6UM-40 and a max load from a reloading manual for a 130 tmk. Now I could be missing something here, but I have plugged in max loads published for each. Even if I changed the 6.5CM to a 140 and used a max load, the 6UM has significantly higher recoil.
 

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MDT SA poly mags are 308. They have LA options that would work.

I have successfully sanded and filled magpul poly mags to work in my wsm. Doesn’t take much work to open poly feed lips to what you need.
Do you have any specific examples of which ones you started with and maybe a before and after picture?
 
Either I am plugging in incorrect data into a recoil calculator, you are massively downloading here, or your perception is incorrect. There is 43% more recoil with the 6UM in an equivalent weight gun compared to a 6.5CM with the attached inputs. There is no way a heavier 6.5CM is recoiling more than a lighter 6UM.

Data used is the published N570 115 DTAC load for the 6UM-40 and a max load from a reloading manual for a 130 tmk. Now I could be missing something here, but I have plugged in max loads published for each. Even if I changed the 6.5CM to a 140 and used a max load, the 6UM has significantly higher recoil.
My recoil calculators say the same, but I frequently hear from many on here that this particular cartridge “feels” more like a 6.5CM rather than 6.5PRC. I’m wondering if there is something to the recoil impulse or if it based on more guys using the Rokstock with these and that impacts the recoil felt???
 
My recoil calculators say the same, but I frequently hear from many on here that this particular cartridge “feels” more like a 6.5CM rather than 6.5PRC. I’m wondering if there is something to the recoil impulse or if it based on more guys using the Rokstock with these and that impacts the recoil felt???
Feel is feel….. data is data. It’s a magnum, so the recoil velocity is fast.
 
I can only say what I feel. Percents in this case are a couple pounds or recoil. A couple factors now that I’m home I weighed it and it’s 8lb 8oz, memory wasn’t serving me well. Second, the manners is apples and oranges to the krg echo the 6.5cm is in, in my opinion. Third, I was being a bit lazy with the 6.5cm, as I thought the 140 eldm is most relatable, and I reload to very similar metrics for a cheap load with staball 6.5. my typical load in that rifle is a 144 with 46.5 or n560 at 2800. I personally can’t tell a significant difference. And I’ve shot them back to back several times.


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I can spot hits very well with my 6UM at 8.5 pounds. I can't consistently spot hits with my 9-pound 6.5 PRC; both are set up almost the same.

Everyone who shoots them side by side says the 6UM feels lighter.

Tanya probably gave me the best feedback, she says the 6.5 PRC feels way snappier :)
 
I will say, you can definitely feel the velocity, it’s a bit “snappier” is the best way I can describe it.


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Haha, I didn't see your post. snappier is the phrase of the day
 
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