Arte et Marte
I'm using a comparator to check the seating length on my .223 Remi with Berger 55gr match bullets.
If I extend the bullet so that it is above the overall length and push the bullet and comparator case into the chamber so that the rifling pushes the bullet into the case the measurement is 2.911".
If I have the bullet seated well into the case, chamber it and use the comparator rod to push the bullet so that it touches the rifling the measurement is 2.850".
So a difference of 0.061".
This makes a considerable difference when I'm looking at how far off the rifling to set the bullet.
Which way do you use to check the seating depth, push the bullet back into the case or push it forward?
Systems Administrator
Could such a small difference be human error?
I would repeat several times and see what the average is.
Could it also be flex in a rod or irregular rifling/lands?
I'd be a bit more worried that its so much longer than the usual 2.260 max colWill the rounds still fit in the magazine?
Dialling code: 01344
61 thou difference. This would be significant when looking to seat a few thou off the lands so I understand your concern here.
I suggest that you take a careful look at the bullets you have used (use a magnifying glass), as depending upon how hard you push on them, there is the potential for the rifling to slightly engrave into the bullet, thus increasing the apparent OL. Also because the rifling will engage the bullet where the shoulder is shallowly tapering, even a tiny difference in bullet diameter at that point will lead to differing measurements.
How about a different approach? Make some up with different lengths in the range you have already found, chamber them, extract them and look for rifling marks on the bullet. The longest one with no marks is just off the lands.
True freedom includes the freedom to make mistakes or do foolish things and bear the consequences.
TANSTAAFL
Registered User
for starters your not using a comparator your using a OAL gauge two totally different toolsOriginally Posted by Gramps
Arte et Marte
Sorry. I should have said that the measurement is using the comparator boss on the vernier.
Measuring the OAL gives a measurement of 2.260" if the bullet is pushed into the rifling by the comparator and 2.318" if the rifling pushes the bullet into the case.
The longer measurement will fit the magazine as I'm using an AICS mag but I'm more concerned with not having the round driven into the rifling when chambering.
I've had problems finding a load that works well in this rifle (Remi Tactical 20" barrel).
If I use Hornady 52gr BTHP the bullet is pushed well into the case compressing the powder to get the SAAMI OAL.
I have checked (with the comparator) the Remi against a Savage FP10 and the throat on the Savage is 0.020" deeper.
Having tried Hornady 52gr and 68gr BTHP, Sierra 52gr and 69gr Match using Vit 133, Reloader 15 and Accurate 2230 without getting good results I'm now trying BLC 2 with Berger 55gr Match.
If this doesn't work It's a new barrel!
Registered User
I think you have serious issues if you cant get a little 223 to shoot with what you have tried,maybe its operator error ?? are you an experienced reloader ???
you seem to be worries about numbers have you loaded a batch up to the lands and pressed them back until you see the group tighten ??
if its not a custom barrel on your rifle you will probably find it dosent like being at the lands as factory guns are throated rather long to suit all makes of bullets
Registered User
Years ago a I bought a Stoney Point OAL gauge complete with the set of cases but never really got consistent chamber measurements with it.
I don't have the facility to drill/tap a fired case so now I just.......
Slightly deform the neck of a case that's been through the rifle enough to grip a bullet;
Insert a bullet into the case mouth just enough to hold it straight and 'felt tip marker pen' round the bullet down to the case neck;
Insert that carefully into the chamber and gently close the bolt to push the bullet against the lands and into the case on the resistance;
Open the bolt, extract the case - if the bullet remains in the chamber just pop it out backwards with a cleaning rod.
The friction of the case neck on the marker pen ink will give you an exact reference point on the bullet to re-insert that into the case and then measure it.......
Easy to repeat to confirm the measurement and a damn sight cheaper than an oal gauge.
A comparator to measure on the bullets ogive is very useful....bullets often differ slightly in length, even between batches of the same make. Either a Stoney Point/Hornady one or a nice shiny one from The Shooting Shed. Whichever you use, just be consistent as the 'oles are likely to be slightly different.
Cheers
fizz
http://www.nightvisionforumuk.com...... you know it makes sense!
Systems Administrator
I'd be tempted to ignore the OAL and to:
1) pick a powder and use something mid range based on suggested reloading data
2) load batches of 3-5 rounds with same powder and 10 thou difference in COL for each batch. Start where you think its hitting the lands and work back.
3) shoot these and find the best load. If you want to be anal then try batches 5 thou either side of this.
4) using this length try batches with 0.5 gr differences to see if powder makes a difference.
I've found in the past that powder (within reason) just changes the height, its the col that makes it accurate. Most of my rifles like to jump, but then again they are all factory.
My Chrony has bought it a couple of times...
Some time back I hade some issues with a Stoney point OAL gauge and it was simple to fix.
I found that the locking collar that locks the rod in place (once the measurement was taken) was loose where it connected to the tube body, so no matter how snugly it seated once I took the gauge out of the action it moved.
Simple answer, check it is tight, also check your modified case is firmly screwed onto the gauge, it makes one hell of a difference.
You also need to be consistent with how you seat the bullet in the lands. I know this sounds daft but you could jam it (needing the bullet to be tapped back out with a rod) or seat it so that it drops out with the OAL gauge. Some jackets are harder than others and will take more or less pressure to seat.
I use finger tip pressure 5 or 6 times and look for the average.
The you have to measure it. A lot of the comparators are pretty poor and only give you a start point. The Stony point ones are touch and go and might need a whole lot of jiggling about to get anything like a decent reading. It really is a rough starting point. You also have to be careful that the jaw of the vernier is flat against the base of the case, its very easy to be a few thou out with little effort.
I would also set one bullet aside so that the Ogive is a constant for every measurement you take.
My approach would be (is) to build a dummy to as near as I can the "touching" OAL, the use a decent vernier/Comparator and work from there.
With reloading, comparators are less about measurement and more (as the name suggests) comparison with a known dummy round and repetition, so you need to be precise and consistent.
I know I see Dave Bonwick as a friend, but that aside I cannot recommend his 2 piece comparators allied to a decent mittutoyo vernier enough. As long as the case is seated properly it needs a light touch to get a good measurement. This gauge has contributed a huge amount to the precision of my loads.
I can get my F/TR loads (with care and consistent brass) to about a thou in OAL consistency using Daves unit and decent kit, this means a lot at 1000yds...mainly I cannot blame the ammo like most effers do
The reason for the accurate ref round is that should you damage or lose part of your kit, you still have a datum and the same bullet. The actual OAL is not that important, what is important is that once you have that measurement, you can repeat it again and again and tune it accurately if needed.
Boring eh?
I'm a maggot in another life you know
Registered User
Hi Gramps,
Both methods you are using will not gve you a reliable and consistant measurement, there is only one way to do this and that is to measure from the muzzle to the bolt-face and once again to a bullet seated to the lands, check out this video on how to do it.
https://www.youtube.com/watch?v=uxFo...Stj7vfAP9XquVA
TB.
Arte et Marte
From what I've read this will not give a consistent measurement when using a hollow point match bullet due to inconsistences in the way the jacket is formed over the core to leave the front exposed. This one of the reasons a comparator is used to always measure to same point on the ogive of the bullet.
I have successfully reloaded for my 357 Marlin underlever, 357 revolver, 308 and for the 223 Savage that my son is now using.
One thing that threw me when I first got the Remington was that if a Hornady 52gr BTHP was loaded to the SAAMI specified overall length the bolt would not close on the round! So I've had to try other bullets to ensure the bolt closes before I can even look at powder weights and distance off the lands, hence my questions on how others use the comparator.
Many thanks for the replies, food for thought on what to do next.
Registered User
You obviously did not grasp the content of the video properly. or did not watch it all the way through mate because it explains that you use the round as a dummy to set your dies too.
Rifle dies seating stems seat the bullets off the ogive not the tip to give consistant base to ogive dimension, taking into account descrepencies in bullet length, it also then explains to use a bullet comparator to check your other rounds are the same.
TB.
Arte et Marte
I have now made a measuring rod as featured in the video.
Using it in manner shown I arrived at a measurement for the overall length of the round when the bullet touches the lands and set the die up to achieve this length.
The Stoney Point comparator was then used to get a reading from the base of the case to the ogive.
This measurement was the same within 0.0005” as I achieved originally with the comparator by having the bullet pushed too far out of the case and allowing the rifling to seat the bullet back into the case.
So I now have a start point verified by two methods of where the bullet touches the rifling for this particular bullet (Berger 55gr Match) which I know will mean the bullet isn't being jammed into the rifling.
Thanks for all of the information.
“Junes1 is a whining bellend”
I noticed the same and theorised that closing an over long bullet in a chamber as a method of finding the lands (or max OAL depending on how you look at it) is unreliable because the bullet is pushed in by the lnads but also retained briefly by them when extracting the round.
therefore the measurement using this method will be longer.
"An infinite number of monkeys banging away at type writers for an infinite period of time will eventually reproduce Hamlet" Thanks to discussion forums we now know this to be untrue.
Arte et Marte
Retention in the lands will depend on how tight the bullet is in the case that's been adapted for the Stoney Point, my case does not grip the bullet, the bullet moves freely.
Additionally even if the bullet was removed entirely from the case placing it back in the case until it butts up against the Stoney Point rod will put it back in place.
This does seem to be born out by the measurement gained from using the rod and collars from the muzzle end.
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