RCBS Matchmaster set setup

[shawn.r2020]

Hey all, new guy here, been reading posts for years off google and finally decided its time. Please be easy on me

Down to it... Im starting to load for 6 ARC, my die set arrived and its time to get after it. Loading for a self built 18" ballistic advantage AR set on getting 1000 yrd+, and to start Im working with 100 Hornady once fired and 200 Starline virgin brass, Federal match SRP, LEVEREVO, 103 gr. ELDX. Wanting to load a ladder for a node.

My RCBS Matchmaster set arrived, now for setup... Im still very new at this precision loading/ bushing die thing... google dosent give much on fine setting these dies. Could any of you folks walk me through getting dialed in and what in what order of op. For set up. Im under impressions on taking out the bushing, sizer button/ decapper, to find shoulder set back _ Lock ring _ reinstall bushing to set its sizing depth on the neck (how far down is best?) _ reinstall (sizer button/decapper retainer included with set?) _ lock it all together and GO AT IT.

This all sound generally correct? Not wanting to oversize or over work brass.. this stuff is hard to come by.

For those that know way more.. Im curious on understanding if/ how to go about various ways to set this sizer die up... with sizer on vs retainer? With or without bushing for body, shoulder, and neck expansion from the inside only? Removing the expander and sizing only using bushing to get neck tension? ... so many variables to adjust vs my standard full length sizing dies.

I appreciate you!

 

[Maurygold]

The only thing you’re trying to setup with the fl die is the shoulder bump. You need a way to measure the shoulder of the bullet. I use hornady comparators because they’re pretty cheap and work.

Set with no bushing or expander set the die into the press and screw it in with the ram all the way up until the fl sizer makes contact with the shell holder. From here screw the die in a tad more so there is some cam over (slight resistance) when hitting the bottom of the stroke with the ram.

Then start sizing brass and adjust down or up until you’re only headspacing 2 thou

 

[WasNH4X]

Step 1. Get black sharpie ,read instructions that came with die,when it gets to the part that says raise press ram ,screw die down blah blah blah.......blacken that shit out so it's never seen again
Step 2 Buy comparator kit and use 7.62 x39 insert....measure fired brass ,with fired primer removed
Step 3 adjust die so sized brass is .002 -.004 shorter that fired brass....if brass is fully fire formed to chamber
Edit: come up with a log/ data book of some kind.......write EVERYTHING down........thank me later

Videos all over u tube showing how to do the above.

A stand alone depriming die is nice to have for step 2

 

[shawn.r2020]

The only thing you’re trying to setup with the fl die is the shoulder bump. You need a way to measure the shoulder of the bullet. I use hornady comparators because they’re pretty cheap and work.

Set with no bushing or expander set the die into the press and screw it in with the ram all the way up until the fl sizer makes contact with the shell holder. From here screw the die in a tad more so there is some cam over (slight resistance) when hitting the bottom of the stroke with the ram.

Then start sizing brass and adjust down or up until you’re only headspacing 2 thou

Apologies for not being very descriptive.. im measuring headspace using hornady headspace, and later when seating to ogive, bullet comparitors.
New starline (measures everwhere spot on and very consistent):
Headspace- 1.1745
Case length- 1.4805
Case thickness- 0.0155
Case mouth (ID/OD)- 0.235/0.266

Hornady once fired:
Headspace- 1.188 +/- .0005
Case length- 1.4835 to 1.490
Case thickness- 0.0135
Case mouth (ID/OD)- 0.248/0.275

RCBS expander ball- 0.241
RCBS neck bushings for 0.004 neck tension- 0.266 (hornady brass) and 0.270 (starline virgin brass)

IF im prepping right, im looking for a headspace of 1.185 (0.003 shoulder bump).

If you guys could please give me a second check brain and give me some free experience advice, im double guessing setup between bushings and prep on virgin brass.. its 0.0105 shorter than my target headspace, neck tension of unprepped neck id at 0.248 gives tension at 0.008 vs if i run the 0.241 expander ball though (would you remove neck bushing and size only expander ball?) and try to get that tension to 0.002?

 

[shawn.r2020]

Step 1. Get black sharpie ,read instructions that came with die,when it gets to the part that says raise press ram ,screw die down blah blah blah.......blacken that shit out so it's never seen again
Step 2 Buy comparator kit and use 7.62 x39 insert....measure fired brass ,with fired primer removed
Step 3 adjust die so sized brass is .002 -.004 shorter that fired brass....if brass is fully fire formed to chamber
Edit: come up with a log/ data book of some kind.......write EVERYTHING down........thank me later

Videos all over u tube showing how to do the above.

A stand alone depriming die is nice to have for step 2

Agree, the "instructions" for general use really leave room for over sizing and stressing brass to fail faster.
I do decap in its own step. Tumble in corncob, and use imperial/RCBS/ or hornady one shot... each depending on what im loading for. Although, my earlier reply, all the hornady measurements were with fired primer still in. Does removal make a big difference? I do use the hornady digital caliper and base for the comparator to give it a solid measurement.

Ive been only relading for maybe a year. .223, 300 blk, 308, 30 carbine, 40 and 9mm.. i know i have a lot to learn although i like to think ive got a good handle on starting out... hope for some tricks yall who know a few things cus youve seen a few, could teach. Ive heard of things like o-rings on die adjustments helping concentric issues?

 

[shawn.r2020]

Additional bonus question, would loading a dummy round locktite style to try and measure where to adjust seating off the lands in an AR be beneficial? I watched a video on it but never tried it. Figure that information would make using the dial seating die more handy.

I do have both RCBS matchmaster and Hornady seating dies, both with dial adjustment, bought the Hornady since its seating stem are specific for some ATips and ELD/ ELDX i have to try and find what the barrel shoots best. I also eventually plan to try CFE223 and Varget along with the Leverevolution. As well as am gathering a full set of bushings to adjust neck tension. And advise on sizer ball, no sizer ball, sizing tips would be appreciated

 

[WasNH4X]

Handloading for competition by Glen Zediker is well worth its cost,if one can be found ,to new and old handloaders . He also wrote two ? ,I think, books on AR rifles . Lots of helpful info there.

It probably sounds like I'm trying to sell books ,my not .....don't have dog in that hunt. Glenn's books have helped me tremendously . I'm a better handloader after implementing a lot of what he wrote ,and it shows on the targets.

Concerning your neck tension,constriction, bullet interference...... .002 is what I try for ,for starters.......bullet O.D. .243, mandrel or sizing ball/ button O.D. .241. I don't use bushing dies ,do over work my necks with standard dies , get 10 / 12 loading on brass before necks give up. I fairly confident if I annealed and didn't over work brass ( used bushing dies),they'd go to 20 maybe more loadings.

Dwell time matters when sizing, slow 5 to 10 count...just use same count........helps during sizing. Hope this helps you out OP and others that read.

 

[shawn.r2020]

Handloading for competition by Glen Zediker is well worth its cost,if one can be found ,to new and old handloaders . He also wrote two ? ,I think, books on AR rifles . Lots of helpful info there.

It probably sounds like I'm trying to sell books ,my not .....don't have dog in that hunt. Glenn's books have helped me tremendously . I'm a better handloader after implementing a lot of what he wrote ,and it shows on the targets.

Concerning your neck tension,constriction, bullet interference...... .002 is what I try for ,for starters.......bullet O.D. .243, mandrel or sizing ball/ button O.D. .241. I don't use bushing dies ,do over work my necks with standard dies , get 10 / 12 loading on brass before necks give up. I fairly confident if I annealed and didn't over work brass ( used bushing dies),they'd go to 20 maybe more loadings.

Dwell time matters when sizing, slow 5 to 10 count...just use same count........helps during sizing. Hope this helps you out OP and others that read.

Appreciate ya, ill look into the book(s), sadly im not usually one to learn from books vs hands on or visually.

Neck tension, or what ever one wants to call it, does .002 seem to be enough for a AR without risking bullet set back?
I bought the bushings and matchmaster dies on a great sale, so its what i have to work with.

Can anyone comment on using the sizer in various configuration.. ie. Without bushing all together just the expander, bushing and decapper holder, etc?

Regarding "dwell time", can you expand on that a bit for me.. ive heard of it but more in regards to the ARs action and not reloading. 5-10 count during what part of the process?

 

[R_A_W]

When bumping the case shoulder, use the Hornady headspace comparators to measure a cartridge that has been fired from your chamber. Hornady comparators aren't machined precisely enough to reliably compare measurements with other people over the internet (I believe SAC & A419 are). Some brass can take 2 firings to fully form to your chamber - there's going to be a little bit of learning through experience here. [The best way to determine your headspace is to find a piece of fired brass that has a slight amount of resistance on bolt close when you have the FP & ejector removed from your bolt. If the bolt "falls close" without resistance, the brass is shorter than your chamber edit: this part is for a bolt gun, not AR]

I do have both RCBS matchmaster and Hornady seating dies, both with dial adjustment, bought the Hornady since its seating stem are specific for some ATips and ELD/ ELDX

The Matchmaster seating die should work fine with those bullets as well.

Can anyone comment on using the sizer in various configuration.. ie. Without bushing all together just the expander, bushing and decapper holder, etc?

Not sure what you mean here

Regarding "dwell time", can you expand on that a bit for me

Dwell time in reloading refers to how long you leave the brass pressed/inserted into a sizing die prior to extraction. When you change something during your sizing process from one piece of brass to the next, you will see variations in how the brass gets sized. The amount of lube, the speed & force you press/ram the brass into the die, & how long you leave the brass inside the die before extracting it will all impact how much the brass gets sized. With regard to dwell time specifically, you will see a difference in headspace if you rapidly cycle one piece of brass in & out of the FL sizer and then cycle a second, different piece of brass by running that brass into the FL sizer die, waiting 10 seconds, then extracting it. If your die is set up properly, the second piece of brass will size more, as the first piece will compress & then "spring back" some. You will have to experiment to determine if & how much dwell time you need

 

[FLIGHT762]

Since you're using a gas Gun, I would measure your fired cases and set your F/L die bump them -.004"-.005" to get 100 % reliability.

From what I've read about the 6 ARC, if you load too hot, you can get belts in the brass in the case web area from over pressure in some 6 ARC gas Gun chambers. I've seen reloading data for bolt Guns and gas Guns.

 

[shawn.r2020]

When bumping the case shoulder, use the Hornady headspace comparators to measure a cartridge that has been fired from your chamber. Hornady comparators aren't machined precisely enough to reliably compare measurements with other people over the internet (I believe SAC & A419 are). Some brass can take 2 firings to fully form to your chamber - there's going to be a little bit of learning through experience here. [The best way to determine your headspace is to find a piece of fired brass that has a slight amount of resistance on bolt close when you have the FP & ejector removed from your bolt. If the bolt "falls close" without resistance, the brass is shorter than your chamber edit: this part is for a bolt gun, not AR]


The Matchmaster seating die should work fine with those bullets as well.


Not sure what you mean here

Dwell time in reloading refers to how long you leave the brass pressed/inserted into a sizing die prior to extraction. When you change something during your sizing process from one piece of brass to the next, you will see variations in how the brass gets sized. The amount of lube, the speed & force you press/ram the brass into the die, & how long you leave the brass inside the die before extracting it will all impact how much the brass gets sized. With regard to dwell time specifically, you will see a difference in headspace if you rapidly cycle one piece of brass in & out of the FL sizer and then cycle a second, different piece of brass by running that brass into the FL sizer die, waiting 10 seconds, then extracting it. If your die is set up properly, the second piece of brass will size more, as the first piece will compress & then "spring back" some. You will have to experiment to determine if & how much dwell time you need

Thank you!
Yea, the measurements i replied with are just for my use and intended for my consistency only, Appreciate you pointing that out. As far as the bolt gun info, thank you, that will be handy when i start working up loads for my 308 bolt.

The hornady seating die was kinda a splurge buy, bought it before buying the matchmaster set. If anything, maybe worth trying both and compare.. worst case i can atleast prevent the seating ring or tip deformation on the Atips ive heard about.

As far as sizing die set up variations, ive heard mention of different ways to go about it, but wasnt indepth, so hoped someone would be able to explain better. I dont understand really myself, just heard its a thing.

Really appreciate the explanation on dwell time, ive always just went with it and havent been mindful of that.. definitely going to now.

 

[shawn.r2020]

Since you're using a gas Gun, I would measure your fired cases and set your F/L die bump them -.004"-.005" to get 100 % reliability.

From what I've read about the 6 ARC, if you load too hot, you can get belts in the brass in the case web area from over pressure in some 6 ARC gas Gun chambers. I've seen reloading data for bolt Guns and gas Guns.

Awesome, thank you, i know ive read that somewhere regarding the headspace, less for bolt/ more for gas concept. I just planned on splitting the difference at .003 and adjusting if needed, not knowing the minimum for gas guns... read soo many opinions on it my head was spinning.

As for the ring at the case web, after tumbling the once fired hornady, im finding a few that seem to have it just from factory hornady black, not all but definitely a fair amount. I was trying to adjust my gas block when some were sent down range, would that possibly be a factor in causing a few of em to do it? Can they be salvaged if they do have it?

 

[tinker]

Additional bonus question, would loading a dummy round locktite style to try and measure where to adjust seating off the lands in an AR be beneficial? I watched a video on it but never tried it. Figure that information would make using the dial seating die more handy.

I do have both RCBS matchmaster and Hornady seating dies, both with dial adjustment, bought the Hornady since its seating stem are specific for some ATips and ELD/ ELDX i have to try and find what the barrel shoots best. I also eventually plan to try CFE223 and Varget along with the Leverevolution. As well as am gathering a full set of bushings to adjust neck tension. And advise on sizer ball, no sizer ball, sizing tips would be appreciated

If you have a hornady overall length tool, it is less work to use the tool. You can use loctite but I wouldn't bother. They will both yield slightly diff numbers but the truth is those numbers don't really matter as long as you are consistent. You may get a couple Thou diff reading one way vs the other but as long you are consistent, that is what matters.

 

[shawn.r2020]

If you have a hornady overall length tool, it is less work to use the tool. You can use loctite but I wouldn't bother. They will both yield slightly diff numbers but the truth is those numbers don't really matter as long as you are consistent. You may get a couple Thou diff reading one way vs the other but as long you are consistent, that is what matters.

I dont have the case length tool yet, unfortunately. I watch a few videos where they take a sized case, case neck sized for bullet slip when chambered, and used locktite to hold it in place. Figure i have everything for that on hand.
My thought is having the bullet comparitor set, if i could get a decent idea of depth to the lands, i can find tune my loads... i know this sort of thing is common in the bolt gun world, is it at all beneficial in an AR?
LONG STORY SHORT, I found out the hard way trying to load 300 blackout, the seating depth concept of mag length can create issues. Hornady Vmax do not like being forced into the lands . Would rather not play that game again.

 

[R_A_W]

You should absolutely get a case comparator asap

 

[shawn.r2020]

You should absolutely get a case comparator asap

I have case comparators and bullet comparitors, need to pick up modified cases and a length tool... been looking, the cost is the big hang up. Im working with a new dad to a 4 month old baby girl budget.. infant daycare is more per month than my rent.. Which has led me to the what can i do with what tools i have concept.

 

[R_A_W]

Gotcha, I misread.

The method you’re suggesting works perfectly fine.

 

[FredHammer]

Gravity Method for DTL:
1. Clean chamber/throat.
2. Muzzle to sky with buttstock on bench.
3. Load a newly sized brass into the chamber with your pinky finger. Press hard on the back of the case head. It should fall by gravity after release.
- This is a test piece of brass to ensure there are no hang-ups/false reads with the brass to chamber fit.
4. Same piece of clean falling brass, load a bullet longer than usual by say .070" over max listed COAL.
5. Slowly insert the round into the chamber pushing very slowly with your pinky.
- Stop pushing when you feel resistance. This is the contact of the bullet with lands. (Turn off the radio, close your eyes, and snail slow to feel this)
- If you stop at the first detection softness, you can free the round with a subtle rap of buttstock on bench. If not, punch out w/rod from muzzle.
6. Seat bullet deeper by .003 and repeat until the round falls freely with gravity when you release your pinky.
- A bullet will stay in the rifling with even .001" into them. So, when it falls free, you are extremely close to the lands. Likely .001-.002"
7. Record that length with a CBTO gauge and record that COAL for that bullet until you get a CBTO gauge. You must do this for each different bullet type, weight, brand, etc.
8. You will now know how far your bullet jump is when you load. Most people seat match bullets starting .000-020 from the lands.

 

[shawn.r2020]

Gravity Method for DTL:
1. Clean chamber/throat.
2. Muzzle to sky with buttstock on bench.
3. Load a newly sized brass into the chamber with your pinky finger. Press hard on the back of the case head. It should fall by gravity after release.
- This is a test piece of brass to ensure there are no hang-ups/false reads with the brass to chamber fit.
4. Same piece of clean falling brass, load a bullet longer than usual by say .070" over max listed COAL.
5. Slowly insert the round into the chamber pushing very slowly with your pinky.
- Stop pushing when you feel resistance. This is the contact of the bullet with lands. (Turn off the radio, close your eyes, and snail slow to feel this)
- If you stop at the first detection softness, you can free the round with a subtle rap of buttstock on bench. If not, punch out w/rod from muzzle.
6. Seat bullet deeper by .003 and repeat until the round falls freely with gravity when you release your pinky.
- A bullet will stay in the rifling with even .001" into them. So, when it falls free, you are extremely close to the lands. Likely .001-.002"
7. Record that length with a CBTO gauge and record that COAL for that bullet until you get a CBTO gauge. You must do this for each different bullet type, weight, brand, etc.
8. You will now know how far your bullet jump is when you load. Most people seat match bullets starting .000-020 from the lands.

Pure brilliance! I have a few calibers.. Ar, bolt, and single shot, i want to do this for. This method seems like it will work all around. Buying modified cases for all of em adds up in a shopping cart. This would give me the ability with only whats already on my bench. Thank you!

Just to clarify, fl size case to just at my fired case headspace, neck sizing for say .001 neck tension, soft seat a bullet long and keep bumping it til it just starts to fall free with gravity? That will give me the location of the lands, then test seating depth for groups.
Instead of doing this process for every bullet, having a hornady bullet comparitor set, would it work to measure the test and record. With new projectile changes, using the recorded measurement as a baseline for seating depth.. would it be safe to assume ogive to be a solid consistency if using the same comparitor?

 

[FredHammer]

Pure brilliance! I have a few calibers.. Ar, bolt, and single shot, i want to do this for. This method seems like it will work all around. Buying modified cases for all of em adds up in a shopping cart. This would give me the ability with only whats already on my bench. Thank you!

Every once in a while I'm worth a damn...saw this method years ago and have been using it on every gun I own.

Just to clarify, fl size case to just at my fired case headspace, neck sizing for say .001 neck tension, soft seat a bullet long and keep bumping it til it just starts to fall free with gravity?

Yes. There is no gradual falling free. It either is in the lands or it falls free when it isn't. Like .0005 in the lands will stay stuck.

That will give me the location of the lands, then test seating depth for groups.

Yes

Instead of doing this process for every bullet, having a hornady bullet comparitor set, would it work to measure the test and record. With new projectile changes, using the recorded measurement as a baseline for seating depth.. would it be safe to assume ogive to be a solid consistency if using the same comparitor?

Oh yes, to test each and every bullet of the same type is a fool's errand. Just record the CBTO for that particular bullet with your Hornady gauge. (I wrote this to a guy who didn't have a CBTO gauge) The ogives of bullets stay more consistent than the lengths. Now, I size shoulders .002-.003 under fired length. Upon firing, that case moves forward that amount with the bullet, so factor this in if you don't want to be shooting at or in the lands. (Which really is of no big deal if you do seat like that)

Even cooler with this method is when I get a new barrel, barrel nut or shouldered prefit. Uninstalled, I can lay it on the table next to the seater press and nail the DTL in a under 2 minutes. Gravity don't lie. LOL.