The 6UM

[The Fish Box]

Wouldn’t he notice a delay in the round going off though?

 

[Holt stewart]

Wouldn’t he notice a delay in the round going off though?

I’m no doctor but the way I understand it a double burn is when you get enough ignition to just push the bullet into the lands and then when the rest of the powder burns you get a pressure spike because it takes more force to get the bullet moving. It all happens way faster than we can perceive. I was more guessing that it’s possible that instead of that he’s just not getting a fast enough ignition to burn all of his powder before it makes its way into the can. Also, if I had to tell someone if they should take anything I say seriously I would strongly advise against it almost all of the time soooo. lol


Sent from my iPhone using Tapatalk

 

[PathFinder]

I noticed something similar with mine. Going back to magnum primers reduced pressure and increased velocity while improving accuracy slightly.

Sent from my Pixel 6 using Tapatalk

 

[ddowning]

Makes a guy wonder if you couldn't just nose ring them and get similar performance to dtacs.

I would think the answer is yes. The nose ring equipment is $$$$. In my experience, and also from talking to guys at matches, that bullet is not the most forgiving design. I have shot a ton of dtacs. They are a pretty forgiving design and can be purchased with the nosering. I don't think there is much to be gained with the 110 over the dtac.

If I were to buy the nosering tooling, I would be more inclined to play with Bergers and see if it would shorten the neck length on the wound cavity to be more in line with tmk and eld. The consistency of Bergers has made a measurable difference in precision several times for me. Being able to hold very small groups for large samples has a pretty noticeable effect on hit percentage as targets get small. Not so much for elk.

 

[ACHILLES]

Makes a guy wonder if you couldn't just nose ring them and get similar performance to dtacs.

I took a pin drill to the 25cal 131aces, they are made by Sierra and pointed also. And opened the Hp to .019” maybe .001-.002 thousands bigger than it was originally. It’s mainly to clean up the edges of the small Hp and get any debris out of there. Made quite a difference in terminal performance on deer and hogs. Exits holes went from 1/2-5/8” to 3/4-1.25” wound channels were larger as well and animals weren’t running as far after. I would think it would be worth a try in 6mm too. Also tested drops out to 800yards with the modified bullets and nothing changed.

 

[wind gypsy]

Those Ace bullets sure sound dreamy. If sierra brought them back a guy might be tempted to build a 25 PRC..

 

[ACHILLES]

Just glad I got a lot at 32cents/pc. I wont be disappointed though when I have to switch to berger/Hornady.
At least you big 6 guys have the dtac still

 

[bow_dozer]

I’m no doctor but the way I understand it a double burn is when you get enough ignition to just push the bullet into the lands and then when the rest of the powder burns you get a pressure spike because it takes more force to get the bullet moving. It all happens way faster than we can perceive. I was more guessing that it’s possible that instead of that he’s just not getting a fast enough ignition to burn all of his powder before it makes its way into the can. Also, if I had to tell someone if they should take anything I say seriously I would strongly advise against it almost all of the time soooo. lol


Sent from my iPhone using Tapatalk

I noticed something similar with mine. Going back to magnum primers reduced pressure and increased velocity while improving accuracy slightly.

Sent from my Pixel 6 using Tapatalk

I just don’t noticeably have hardly any signs of too much pressure. Bolt lift is normal, back end of the case looks good, no creators, primers are tight.
I’m not opposed to going to a 215, but accuracy and ES have been phenomenal with this load. I shot 6 times on Saturday before the can popped. 3295 min and 3301 max. @Formidilosus are you running 210s in yours?

 

[Holt stewart]

That seems like crazy velocity out of a 20” barrel. You’re 160+fps faster than I’m getting out of my 18” Krieger. If everything seems happy pressure wise I certainly wouldn’t complain or change anything if I were you, nothing wrong with free velocity. I’m interested to hear what the suppressor manufacturer has to say when you talk to them.


Sent from my iPhone using Tapatalk

 

[bow_dozer]

Just dropped what was left of the can off today. Steve was awesome to talk with and troubleshoot ideas/opinions of what happened. There was/is a stress fracture below the baffle/weld line. He thinks this was the culprit. He told me he would work on it asap and have the can back to me by next week.
We talked about load data and gun specs, he has 0 issue or concerns with where I am at. (Also said he wants to see this gun as it sounds like a good time )

 

[6.5x284]

Just dropped what was left of the can off today. Steve was awesome to talk with and troubleshoot ideas/opinions of what happened. There was/is a stress fracture below the baffle/weld line. He thinks this was the culprit. He told me he would work on it asap and have the can back to me by next week.
We talked about load data and gun specs, he has 0 issue or concerns with where I am at. (Also said he wants to see this gun as it sounds like a good time )

Can't ask for anything better than that!

 

[bow_dozer]

That seems like crazy velocity out of a 20” barrel. You’re 160+fps faster than I’m getting out of my 18” Krieger. If everything seems happy pressure wise I certainly wouldn’t complain or change anything if I were you, nothing wrong with free velocity. I’m interested to hear what the suppressor manufacturer has to say when you talk to them.


Sent from my iPhone using Tapatalk

I was talking with Ryan and I was convinced I had the slowest 6um to date. First rounds down the pipe I was 3100 at 66, 3170 at 66.5. ES and group size were great for most of the ladder, besides 66…
Anyways, we shot 15 shots initially, ending on 66.5 @ 3170
I don’t know what changed, same Garmin chrono, same load, same range but went out a week later and first shots were 3290 ES was like 6 or 7, until I blew the can off and it increased to 3315 that shot lol.

Is this where Ryan says “Wildcattin” fun??

 

[Holt stewart]

I was talking with Ryan and I was convinced I had the slowest 6um to date. First rounds down the pipe I was 3100 at 66, 3170 at 66.5. ES and group size were great for most of the ladder, besides 66…
Anyways, we shot 15 shots initially, ending on 66.5 @ 3170
I don’t know what changed, same Garmin chrono, same load, same range but went out a week later and first shots were 3290 ES was like 6 or 7, until I blew the can off and it increased to 3315 that shot lol.

Is this where Ryan says “Wildcattin” fun??

That’s basically the opposite of what I had happen. I fire formed three hundred pieces of brass (one hundred of which I ruined with the large rifle primers). I then loaded my way up to pressure at 68 grains, dropped back to 66 and I was at 3140fps. Once I tested for accuracy I loaded up 200 rounds and started shooting steel. Somewhere in the first 150 rounds I started having elevation problems as well as pour grouping so I ran them past the chrono and they had dropped all the way down to 2970ish. Just to make sure I hadn’t made a mistake when I loaded them I threw another five together and they were the same speed. After I added a grain and a half it brought me back up to about 3120 average and the accuracy improved but it didn’t seem to last because I loaded another 100 rounds and towards the end things started falling apart again. I should have chronod them again but I was frustrated so I pulled the barrel and stuck my 6.5 saum barrel on to shoot until I can run down to my smith and have him bump tge 6um forward to see if it helps just out of curiosity. Either way I’ve got a new barrel that I’m gonna have spun up and just use that one for fire forming. At least components are getting cheaper and more available every day right lol


Sent from my iPhone using Tapatalk

 

[The Fish Box]

How did you ruin the brass with large rifle primers?

 

[Grundy53]

Those Ace bullets sure sound dreamy. If sierra brought them back a guy might be tempted to build a 25 PRC..

Just use 134 ELD-Ms

Sent from my SM-S901U using Tapatalk

 

[Holt stewart]

How did you ruin the brass with large rifle primers?

Thats what caused the insufficient ignition giving me the double burn which caused pressure spikes while I was fire forming. Once I went to magnum rifle primers my pressures went back to normal and everything started working out.


Sent from my iPhone using Tapatalk

 

[ThatDUDE]

This bullet shoots very well in my 6gt at 2920fps approx 10k off lands. A 6cm would likely node in around 3020-3050. I have not yet killed anything with it, that'll be next year.

I was wondering what barrel length you are running?

 

[khuber84]

I was wondering what barrel length you are running?

In the gt? 24", 36.4gr H4350.

 

[JBradley500]

Can you rechamber a (fast twist) 243 to 6UM?

 

[Mike D Texas]

Can you rechamber a (fast twist) 243 to 6UM?

Yes but you will need a new bolt.


Sent from my iPad using Tapatalk Pro