I am about to try and determine distance to lands on my new RPR 6.5 mm. I do not have an OAL gauge so planning on seating a bullet at different depths and marking them with permanent marker until I find exact length. I will be using same bullet and brass each time. My question is... do I need to remove the bullet from casing each time with puller before seating it again at different length or can I just stick cartridge back in press and seat it deeper?
Lands question
- Thread starter Chernobyl
- Start date
It's worth the cash to get the headspace guage and the oal length guage from hornady. Youll need a comparator mic insert and not measuring to the bullet tip. Measuring coal to the tips is not consistant due to bullet variation. You want to measure to the ojive. These are tools you'll use in many multi use scenarios.
Be careful seating the same bullet in the same brass over and over as the spring back on the brass can cause variation in the seating depth of the die when you go back or a virgin bullet and brass combo.
Be careful seating the same bullet in the same brass over and over as the spring back on the brass can cause variation in the seating depth of the die when you go back or a virgin bullet and brass combo.
My problem using the OAL gauge is that I seem to get a different measurement every time I check (using the same bullet/case). Not major but up to .05". I try hard to use constant pressure.
The rpr is difficult to get a good feel for the wheeler method even with the firing pin stripped (which isn’t the easiest) with the bolt release that’s always jamming on it. But otherwise yeah, do it like the wheeler method but with sharpie on the bullet.
I do it in big .010 steps until it goes from clear land imprints to none. Seating further without pulling is fine.
Then I will do another bullet and work it down in fine increments starting at the last land imprint. Then another. Then another. Then another. Find out where several in a row end up at the same point. And there you have it. Once you get the feel down it goes much faster. The first time can be tedious but when you finally find that point where it goes cleanly you have an A-ha! moment.
I do it in big .010 steps until it goes from clear land imprints to none. Seating further without pulling is fine.
Then I will do another bullet and work it down in fine increments starting at the last land imprint. Then another. Then another. Then another. Find out where several in a row end up at the same point. And there you have it. Once you get the feel down it goes much faster. The first time can be tedious but when you finally find that point where it goes cleanly you have an A-ha! moment.
There are several ways to skin this cat. Before I got a Comparator, I made something similar and got good results with it.
- I took a case, 223 in this case, and made a single cut across the neck opening with an Exacto hobby saw. I then used needlenose pliers(any kind will work), and gently squeezed the two sides together so there was enough tension to hold a bullet in place. I put the bullet in the chamber and closed the bolt firm enough to push the bullet to the land but not into them. A light touch goes a long way.You want the case and bullet to come out together. You can get a relative measurment from that.
- The video featured above is about the best one I've ever seen on the subject. When you get through, you have a dummy round which you can use to set your seating stem for that particular bullet.
- Buy a Hornady Comparator. You will use it a lot and it will become one of your best friends. Hope some of this helps.
Yup. Does work pretty good. I use a Dremel and just slowly drop it down the center axis of the case and oscillating it back and forth to open the slit. Going down to the bottom of the shoulder seems to give a little more flexibility for tension on certain cases.
Appreciate the tips. I have a bullet comparator just do not have a hornady oal gauge and trying to figure out my seating depth tonight. Will try the above methods. Now I just need to remove the firing pin
As long as you don't offend the POPO on the the site all should be ok, all joking aside I used a casing fired in the rifle I was setting up at the time long before I started using the Hornady/ Stoney Point case gauges with a slight dent in the case mouth and a bullet colored with a sharpey to great effect it just takes a little more trial and error and feel for what your doing to get right.
Update... after two hours and with the help of the tips above, I determined distance to lands was 2.271 (+\- .001). Thanks again for the help guys.
That’s a good way to do it. I don’t close the bolt on the round though, because the bullet has a tendency to stick in the rifling and will pull out of the case.
The best way is to push the round in under finger pressure and then eject it using a cleaning rod from the opposite end.
You push it in with your finger or you could do still do it with the bolt, just dont rotate the bolt down grinding it into the lands.
I meant to say once you've seated it touching, how do you push out the bullet & cartridge without altering the seating you just measured?
You quoted it already...
Cleaning rod.
If the cleaning rod requires enough pressure to move the bullet back into the case you need to
a) not hold the case inside the chamber and let it be removed
b) use a case with a tad more neck tension on the bullet
c) not slam the hell out of the rod down the barrel or
d) use a case thats sized smaller so that it isnt getting jammed into the chamber itself and resisting extraction.
I've watched numerous people doing this in pretty much the same fashion but I never saw anyone do it without using a bolt. I'm not saying it's wrong just that I'd think you'd want to replicate the actual fitment you'd have when firing a round.
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